JUDGMENT : MANOJIT BHUYAN, J. 1. The essence of the suo motu revisional power vested in the Deputy Commissioner of Taxes, Zone-B (hereinafter alluded to as "DCT") under section 36 of the erstwhile Assam General Sales Tax Act, 1993 (in short, "the Act") is the bone of contention in the present proceeding. Challenge to such power is made vis-à-vis the revisional order dated July 10, 2011 and notice of demand dated July 18, 2011 of the DCT as well as the order of the Assam Board of Revenue dated May 19, 2014 affirming the stand of the DCT, save and except in respect of the direction made to the assessing authority for revising the assessment order. The Board held that the assessment made be deemed to be the assessment of the revisional authority as a part of his revisional order. Facts noticed in the following paragraphs are to be essentially traversed, though somewhat arduous. Relevant to the case is that the petitioner-company had submitted its return of turnover for the assessment year 2004-05 before the assessing authority, i.e., the Assistant Commissioner of Taxes, Tezpur along with the audited statement of accounts and the audit report for assessment under section 17(4) of the Act. Pursuant to the order of assessment dated July 5, 2007 the assessing authority issued Notice dated May 26, 2009 directing the petitioner-company to submit explanation as the assessment, upon scrutiny, was found to be erroneous and required rectification under section 37 of the Act, in that, the percentum of deduction allowed in the assessment was more than 25 per cent, as allowable under section 8(3)(iv)(b) of the Act. The proposed rectification was confined to the deductions allowed on account of labour and other charges from the works contract. The petitioner-company submitted explanation with prayer to drop the proceedings for rectification. It would be useful to reproduce the said Notice dated May 26, 2009, which is as under: "Government of Assam Office of the Assistant Commissioner of Taxes, Tezpur No : 207 Date : May 26, 2009 To: M/S. Gammon India Ltd., Tezpur. Sub: Rectification of assessment for the year 2004-05 under the AGST Act, 1993. Sir, Where on scrutiny of your case records for the year 2004-05 it was found that contain claims made by you were reduced during completion of assessment for that year. Sub: Rectification of assessment for the year 2004-05 under the AGST Act, 1993. Sir, Where on scrutiny of your case records for the year 2004-05 it was found that contain claims made by you were reduced during completion of assessment for that year. The details are shown below: Item Your claim for deduction Deduction Labour charges Rs.7,09,88,858 Rs.5,66,23,072 Other charges Rs.4,40,79,562 Rs. 4,30,00,000 However, as per provisions of section 8(3)(iv)(h) of the AGST Act, 1993, the percentum of deduction allowable should not be more than 25 per cent, and rate of tax leviable is eight per cent. Since the amount of deduction allowed in the assessment is more than 25 per cent, as observed, the assessment is erroneous and is liable for rectification, as the mistake is apparent from records, under section 37 of the concerned Act. You are, however, given an opportunity to put forward your explanation, if any writing before the undersigned at his office positively on June 8, 2009 failing which action shall be taken as contemplated. (P. Baruah), Assistant Commissioner of Taxes, Tezpur." 2. For reasons not categorically specified, the matter did not proceed and no action whatsoever was taken on the notice dated May 26, 2009. Subsequently, on July 8, 2010 a letter was issued by the higher authority, i.e., the DCT directing the petitioner-company to produce the books of accounts like labour payment documents, contract document, payments received, goods supplied cash book, ledger, etc., relating to different works contract at various places in Assam for the period ending 2004-05, fixing July 19, 2010 as the date of hearing. The petitioner-company made reply on July 16, 2010 indicating that assessment for the year 2004-05 had since stood completed and the relevant data and documents had been produced before the assessing authority, whereupon the assessment order was issued after due verification. Further, the petitioner-company was faced with extreme difficulty to retrieve relevant documents for the purpose of re-verification. Request was made to apprise the reason requiring it to produce the books of account once again for the subject period. The matter proceeded with the DCT issuing the letter dated July 23, 2010 citing that the grounds urged by the petitioner-company did not deserve consideration when a tax authority was exercising his statutory powers for safeguarding the interest of revenue of the State. The matter proceeded with the DCT issuing the letter dated July 23, 2010 citing that the grounds urged by the petitioner-company did not deserve consideration when a tax authority was exercising his statutory powers for safeguarding the interest of revenue of the State. The plea taken by the petitioner-company that assessment proceeding had since stood completed, the same was held to be irrelevant as the present action was for re-verification of the books of account as per law. As regards the plea that the books of account had been shifted to Mumbai, the DCT held that the petitioner-company was obliged to make necessary arrangement for producing the same before the tax authority of Assam as and when made expedient for the purpose of safeguarding revenue. The DCT directed production of the books of account, as sought for earlier, fixing August 2, 2010. The petitioner-company again replied by its letter dated July 30, 2010 that the relevant data/documents called for were six years old and retrieving the same from various godowns at the head office and from different sites was a time consuming affair. Request was made for grant of 4 (four) weeks time enabling compilation of the data/documents for the verification exercise. This request was acceded to vide DCT's letter dated August 2, 2010, fixing September 2, 2010 as the next date for production of the books of account. It was also observed that the petitioner-company had earlier availed of a month's time for doing the same and, therefore, no further extension would be entertained. The exchange of letters came to a halt with the letter dated October 9, 2010 of the petitioner-company whereby the DCT was informed that it had already attended two hearing along with relevant documents. However, it was stated, that due to unavoidable circumstances it would not be able to attend the next hearing on October 11, 2010. Request was made for extension of time by another month. 3. On June 17, 2011 a show-cause notice was issued under the hand of the DCT towards suo motu revision of the assessment order dated July 5, 2007 for the year 2004-05 under the provisions of the Act. The revisional authority, i.e., the DCT observed that examination of the proceedings of the assessment order dated July 5, 2007 disclosed that the same is erroneous in so far as it is prejudicial to the interest of the Revenue. The revisional authority, i.e., the DCT observed that examination of the proceedings of the assessment order dated July 5, 2007 disclosed that the same is erroneous in so far as it is prejudicial to the interest of the Revenue. Facts and grounds cited in the said show-cause notice are as under: "(i) The assessing officer although found that the deduction claimed on count of labour and other charges in return/accounts filed by you for the year 2004-5 was on the higher side, within the meaning of rule 14(1)(b) of the erstwhile A.G.S.T. Rules, he did not restrict the allowable deduction within the limit set out in the said rule 14(1)(b). (ii) The returns filed by you including the 'consolidated revised' return for the year also appear to be ab-initio defective and incomplete inasmuch as the details of purchases and stock of goods involved in works contract are not declared in column F of annexure-I appended to the returns. The defective return (S) made the case even stronger for not allowing the claim of deduction on count of labour and other charges beyond the limit prescribed by the rule 14(1)(b). (iii) Verification of payment vouchers records pertaining a portion of the works contract receipts and others documents produced by you during examination of accounts at this and also revealed that you have claimed declaration on account of following works, which ought to have been included in taxable turnover. (a) Cost of boulder collection from river; (b) Cost of boulder crushing; (c) Cost incurred in carrying boulder and send to worksite; (d) Cost loading, unloading of materials like cement, steel, boulder, chips, etc. (e) Royalty paid for procuring boulder, sand, against back drop of the settled position of law that for the purpose of ascertaining the value of goods which are involved in execution of works contract for the purpose of imposition of tax, the cost of procurement, transportation of goods to place for the purpose of incorporation in works contract has to be added to the taxable turnover, the claim of deduction on count of labour and other charges and allowed in the assessment order dated July 5, 2007 is found further vitiated. (iv) It also appears that you claimed erroneous deduction for the entire establishment cost comprising salary of staff, maintenance of site, over head expenses without making apportionment of such cost relatable to deemed sale of goods/materials while executing the works contract. The first assessing authority altogether failed to take note of discrepancy while allowing the deduction on count of labour and other charges. (v) The first assessing authority also failed to obtain documents like income/expenses account, profit and loss account, balance sheet, etc., pertaining to your business before finalizing the assessment. (vi) The erroneous assessment order has given rise to a short levy of principal tax amounting to Rs. 43,14,189 as shown below: 1. Gross works contract receipt Rs.18,58,80,878 2. Less : admissible of tax supported declared goods other charges at Rs.7,44,850 3. Less : admissible deduction on count and other charges at 25% of (1-2) above Rs.4,62,84,007 4 Less : admissible deduction under section 8(3)(vi Rs.1,12,30,678 5. Currently determined N.T.O. Rs. 12,76,21,343 6. Currently leviable tax and sales tax at 8.8% Rs. 1,12,30,678 7. Tax to be actually levied in the assessment order dated July 5, 2007 Rs.59,16,489 8. Short levy of tax taking place (6-7) of above Rs.43,14,189.” The petitioner-company was asked to show-cause by June 24, 2011 as to why corrective order under section 36(1) of the Act read with section 109(2)(b) of the Assam Value Added Tax Act, 2003 should not be passed modifying the original assessment order dated July 5, 2007 and enhancing the demand of payable tax/interest, etc. 4. In its reply dated July 5, 2011, the petitioner-company reiterated its earlier stand by making reference to the letters earlier exchanged by and between the parties. Preliminary submissions were made, both in law and in facts, with request for a revised date for making final submissions as well as for affording opportunity of personal appearance. The petitioner-company contended that the provisions under section 37 of the Act has been incorrectly and improperly invoked as the same only relates to making rectification of any arithmetical mistake or other mistake of a factual nature apparent from the record of the case within a period of three years. Having regard to the date of the assessment order, i.e., July 5, 2007, the proceedings put in motion was barred by limitation. Having regard to the date of the assessment order, i.e., July 5, 2007, the proceedings put in motion was barred by limitation. Further, in the absence of a suitable legal mechanism for computing the taxable turnover, the proceeding was liable to be dropped. According to the petitioner-company, the taxable turnover in terms of the value of goods resulting in deemed sales had been disclosed and tax was accordingly paid. Reference was made to section 2(34) of the Act, which defines "sale price" as well as to sub-clauses (a) to (c) of sub-rule (1) to rule 14 of the Assam General Sales Tax Rules, 1993, which provides for determination of taxable turnover in case of works contract, as being bad in law in the absence of a statutory mechanism for computing taxable turnover. It was stated that the exercise initiated by the show-cause notice dated June 17, 2011 was without jurisdiction and without sanction of law and any demand of tax would be in gross violation of article 265 of the Constitution of India. 5. The assessment made by the DCT in exercise of powers under section 36(1) of the Act read with section 109(2)(b) of the Assam Value Added Tax Act, 2003 concluded with the order dated July 10, 2011. By the said order the original assessment order dated July 5, 2007 was cancelled. A fresh demand notice was issued by the DCT on July 18, 2011. As the order dated July 10, 2011 forms the crux of the case in hand, the same is reproduced for ready reference: “The Assam General Sales Tax Rules, 1993 Form XA Assessment order sheet (See Rule 29) Name of the dealer M/s Gammon India Ltd. Address Sadilapur, Jalukbari, Guawahati Registration No. TEZ/GST/383A, 383B and 383C Period 2004-05 Assessment made Section 36(1) of the AGST Act, 1993 read with section 109(2)(b) of the AVAT Act, 2003 Date of assessment July 10, 2011 The dealer was originally assessed under the AGST Act, 1993 for the year 2004-05 on July 5, 2007 by the Assistant Commissioner of Taxes, Tezpur, under whose jurisdiction the dealer was initially registered. The case record was, however transferred to Guwahati Unit-B as the dealer's business shifted to a place under its jurisdiction. The case record was, however transferred to Guwahati Unit-B as the dealer's business shifted to a place under its jurisdiction. In course of later scrutiny of original assessment order asked July 5, 2007 and also the return filed by the dealer, it came to the notice of the dealer that the original assessment order was erroneous in so form as it was prejudicial to the interest of revenue upon following facts and grounds: (1) The assessing officer although found that the deduction claimed on count of labour and other charges in return/accounts filed by the dealer for the year 2004-05 was on the higher side within the meaning of rule 14(1)(b) of the erstwhile AGST Rules, he did not restrict the allowable deduction within the let out in the said rule 14(1)(b). (2) The returns filed by the dealer including the 'consolidated revised' return for the year also appeared to be ab initio defective and incomplete in on as much as the details of purchase or stock of goods involved in works contract were not declared in column F of annexure I appended to the returns. The defective return(s) made the case stronger for restricting the deduction on count of labours and other charges within the limit prescribed by rule 14(1)(b) of the AGST Rules, 1993. (3) The dealer was found to have submitted payment voucher records pertaining to a portion of the works contract receipts and also some statements showing availment of deduction on count of following input cost incurred in making deemed sale of materials in course of execution of works contract which were in fact taxable turnover for the purpose of levying tax. (f) Cost of boulder collection from river; (g) Cost of boulder crushing; (h) Cost in carrying boulder and sand to worksite; (i) Cost loading, unloading of materials like cement, steel, boulder, chips before their incorporation in works contract; (j) Royalty paid for procuring boulder, sand, etc. (4) The dealer also claimed and was allowed in the original assessment order erroneous deduction for the entire establishment cost comprising salary of staff maintenance of work site, overhead expenses without making apportionment of such cost relatable to deemed sale of goods/materials in execution of contract and without adding the same to the taxable turnover. (4) The dealer also claimed and was allowed in the original assessment order erroneous deduction for the entire establishment cost comprising salary of staff maintenance of work site, overhead expenses without making apportionment of such cost relatable to deemed sale of goods/materials in execution of contract and without adding the same to the taxable turnover. It is also judicially settled that assessable value of materials undergoing deemed sale in course of works contract should be determined according to its value or price at the time of incorporation in works contract, i.e., including all the input cost suffered before incorporation in works contract. In Gannon Dunkerley & Co. v. State of Rajasthan [1993] 88 STC 204 (SC), the Supreme Court of India made following observations: '(i) . . . . Since the taxable event is the transfer of property in goods involved in the execution of a works contract and the said transfer of property in such goods takes place when the goods are incorporated in the works, the value of the goods which can constitute the measure for the levy of the tax has to be the value of the goods at the time of incorporation of the goods in the works and not the cost of acquisition of the goods by the contractor. . . . (ii) The value of the goods involved in the execution of a works contract will have to be determined by taking into account the value of the entire works contract and deducting there form the charges towards labour and services which would covers : (a) labour charges for execution of the works; (b) amount paid to a sub-contractor for labour and services; (c) charges for planning, designing and architect's fees; (d) charges for obtaining on hire or otherwise machinery and tools used for the execution of the works contract; (e) cost of consumables such as water, electricity, fuel, etc., used in the execution of the works contract the property in which is not transferred in the course of execution of a works contract; (f) cost of establishment of the contractor to the extent it is relatable to supply of labour and services; (g) other similar expenses relatable to supply of labour and services; (h) profit earned by the contractor to the extent it is relatable to supply of labour and services. The amounts deductible under these heads will have to be determined in the light of the facts of a particular case on the basis of the materials produced by the contractor. (iii) In cases where the contractor does not maintain proper accounts or the accounts maintained by him are not found worthy of credence it would be permissible for the State Legislature to prescribe a formula for determining the charges for labour and services by fixing a particular percentage of the value of the works contract and to allow deduction of the amount thus determined from the value of the works contract for the purpose of determining the value of the goods involved in the execution of the works contract .... (iv) It would be permissible for the State Legislature to tax all the goods involved in the execution of a works contract at a uniform rate which may be different from the rates applicable to individual goods, because the goods which are involved in the execution of the works contract when incorporated in the works can be classified into a separate category for the purpose of imposing the tax.' Nevertheless, the dealer was issued a specific show-cause notice vide Memo No. 270 dated June 27, 2011 specifying the facts upon which suo motu revision proceedings has been contemplated. The dealer's representative appeared on June 24, 2011 and prayed for a time of 30 days for furnishing reply to the show-cause notice. Such time was, however, granted only up to July 5, 2011. On the fixed date of July 5, 2011 Sri Subir Pyra, an official of the firm and furnished written submission vide their letter No. Ref. The dealer's representative appeared on June 24, 2011 and prayed for a time of 30 days for furnishing reply to the show-cause notice. Such time was, however, granted only up to July 5, 2011. On the fixed date of July 5, 2011 Sri Subir Pyra, an official of the firm and furnished written submission vide their letter No. Ref. NBBA/26/19694/11, dated 5/7/2011 perusal of the same, however, reveals that the dealer has not furnished any grounds or materials refuting the finding of the Revenue as to the inadmissible claims of deduction on count of labour and other charges made in the return and account by the dealer and erroneously allowed at the time of original assessment of the dealer in his reply dated July 5, 2011 although points out that the total turnover in case of works contract spreading over more than one year can be determined by the value of goods purchases as per provision of subclause (a) to sub-rule (1) of rule 14, he has failed to furnish such figure of purchases either in returns or even while submitting his reply. Further the challenges might to be raised against vires of the statutory provisions in his reply dated is found not maintainable. I therefore set aside the original assessment order dated July 5, 2007 by exercise of power conferred upon me by section 36(1) of the erstwhile AGST Act, 1993 read with section 109(2) of the AVAT Act, 2003. Since the dealer has claimed deemed sale of locally purchased declared goods at Rs. 7,44,850 in return and the first assessing officer also found the claim supported by proper document, deduction of Rs. 7,44,850 is found straightway allowable at 25 per cent, of the remaining works contract receipt of Rs. 18,51,36,028 after deduction of value of declared goods of Rs. 7,44,850 from the gross receipt of Rs. 18,58,80,878. 7,44,850 in return and the first assessing officer also found the claim supported by proper document, deduction of Rs. 7,44,850 is found straightway allowable at 25 per cent, of the remaining works contract receipt of Rs. 18,51,36,028 after deduction of value of declared goods of Rs. 7,44,850 from the gross receipt of Rs. 18,58,80,878. Therefore, the assessing officer is directed to revise the assessment order as below: G.T.O. Detd Rs.18,58,80,878 ….(1) Less : Sale price of declared goods purchased locally within the State Rs.7,44,850 …(2) Less at : 25% of (1-2) above Rs.4,62,84,007 Less under section 8(3)(vi) Rs.1,12,30,678 N.T.O. Rs.12.76.21.343 Tax assessed at 8.8% Rs.1.12.30,678 Less : Credit to tax payment allowed as per original assessment order Rs.69,10,217 Tax paid vide challans dated October 12,2009 (part-amount) subsequently original assessment order dated July 5, 2007 Rs.6,272 Balance payable principal tax Rs.43,14,189 Interest on Rs.43,20,461 From 1.5.5 to 11.10.2009 at 24% p.a. Rs.46,05,600 Interest on Rs.43,14,189 From 12.10.09 to 10.7.2011 at 24% p.a. Rs.17,86,078 Total interest levied Rs.63,91,678 Total payable Rs,1,07,05,867 Issue fresh demand notice after cancelling the previous assessment order dated July 5, 2007 and demand notice. Sd/ (A.K. Sutradhar) Deputy Commissioner of Taxes, Guwahati Zone-B. Date July 18, 2011. Memo No. 498-501 Date July 18, 2011 Copy to: 1. The Commissioner of Taxes, Assam for information. This has a letter No. CF(a)12/2009/912, dated April 30, 2011. The matter relates to AG's Draft Para. 2. The Superintendent of Taxes, B Unit, Circle-99 for information. He is requested to issue fresh demand notice as per order, cancelling the previous assessment order dated July 5, 2007. The copy of the fresh demand notice may be send to the undersigned. 3. M/S. Gammon India Ltd., Sadilapur, Jalukbari, Guwahati. (A.K. Sutradhar), Deputy Commissioner of Taxes, Guwahati Zone-B." 6. The aforesaid order dated July 10, 2011 was initially assailed in W.P.(C) No. 4130 of 2011 but on account of availability of the statutory appeal provided under section 5A of the Act, the same was relegated for availing the alternative remedy. The appeal filed before the Assam Board of Revenue, Guwahati, registered and numbered as Case No. 70 STA/2012 was heard and dismissed vide judgment and order dated May 19, 2014. Interference to the order dated July 10, 2011 was made to the limited extent by deleting the direction given by the revisional authority to the assessing authority to revise the assessment order. Interference to the order dated July 10, 2011 was made to the limited extent by deleting the direction given by the revisional authority to the assessing authority to revise the assessment order. The Board held that the assessment so made be deemed to be the assessment of the revisional authority as a part of his revisional order. Aggrieved, the present writ petition is laid. 7. As the determination of the present case rests on the scope and ambit of the suo motu power vesting on the revisional authority under section 36(1) of the Act, it would be prudent to begin with by reproducing the same: "36. Revision of order by the Commissioner.--(1) The Commissioner may call for and examine the records of any proceeding under this Act and if he considers that any order passed therein by any person appointed under sub-section (1) of section 3 to assist him is erroneous in so far as it is prejudicial to the interests of the Revenue, he may, after giving the dealer or the person to whom the order relates an opportunity of being heard and after making or causing to be made such enquiry as he deems necessary, pass such order as the circumstances of the case justify, including an order enhancing or modifying the assessment of tax or penalty or cancelling such order and directing that a fresh order should be made: Provided that no order under this sub-section shall be made after the expiry of eight years from the end of the financial year in which the order sought to be revised was made. Explanation : The provisions of this sub-section shall apply, notwithstanding that the order sought to be revised has been made the subject of any proceeding by way of appeal, in respect of matters not actually considered and decided in such proceedings." 8. Arguments advanced by Dr. A.K. Saraf, learned senior counsel for the petitioner-company, may now be noticed. He opens by saying that rectification of mistakes in an assessment order is a power vested with the assessing authority and the DCT cannot encroach upon the same. It is contended that the purport of the notices issued by the assessing authority on May 26, 2009 and that of the DCT on June 17, 2011 are one and the same. He opens by saying that rectification of mistakes in an assessment order is a power vested with the assessing authority and the DCT cannot encroach upon the same. It is contended that the purport of the notices issued by the assessing authority on May 26, 2009 and that of the DCT on June 17, 2011 are one and the same. The additional grounds mentioned in the notice dated June 17, 2011 of the DCT only qualifies the content and purport of the notice issued by the assessing authority. In fact, no new materials or grounds have been assigned. Although section 36(1) of the Act empowers the revisional authority to initiate suo motu revisional proceedings on being satisfied that an order passed by an officer appointed to assist him is erroneous in so far as the same is prejudicial to the interest of Revenue, such power would not invest the revisional authority to initiate enquiry trenching upon the powers which are expressly reserved on other authority under the Act and the Rules. According to Dr. Saraf, the power under section 36(1) of the Act can come into play when there is a jurisdictional error in making the assessment or in passing any other order, as distinguished from any other error that may have occurred in the determination of the extent or quantum of liability to tax. In the present case, as contended, there was no jurisdictional error in the order of assessment and, therefore, the DCT was without power and authority to initiate suo motu revision proceeding, far from passing the order dated July 10, 2011. Reliance is placed in Rajendra Singh v. Superintendent of Taxes reported in [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449. Dr. Saraf also makes reference to the case in Santalal Mehendi Ratta (HUF) v. Commissioner of Taxes reported in [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197, to say that this court have reiterated what is erroneous and prejudicial to the interest of Revenue enabling exercise of suo motu revisional power. In Santalal [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197, the Single Bench of this court held that where an order of assessment had been passed within the limits of the jurisdiction of the assessing authority, even if considered to be wrong by the revisional authority, the same would not attract the exercise of suo motu revisional powers. In Santalal [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197, the Single Bench of this court held that where an order of assessment had been passed within the limits of the jurisdiction of the assessing authority, even if considered to be wrong by the revisional authority, the same would not attract the exercise of suo motu revisional powers. Taking it further from the said judgment, Dr. Saraf contends that even if the revisional authority disagrees with the assessing authority or primary authority on matters relating to deductions allowable under the statute, the same may give rise to a situation where the order rendered by the primary authority is wrong or erroneous, as commonly understood, but that would not be a facet of the erroneous decision falling within the meaning of the expression appearing in section 36 of the Act. Dr. Saraf emphatically submits that it is no more res integra that the expression employed in section 36 is confined to correction of jurisdictional errors, else there would be no distinction in the corrective power conferred upon different authorities by the statute for application in different situations. It is contended that intermingling of powers would only result in confusion and uncertainty, a situation not contemplated by the Act. On the facts of the present case, it is submitted that if rectification of the assessment, as sought to be done, did not fall within the purview of section 37 of the Act, it was a case under section 18 of the Act, permitting an enquiry where the assessing officer had reason to believe that any exemption or deduction has been wrongly allowed or allowed in excess to a dealer. To permit exercise of suo motu revisional powers under section 36, in the facts of the case, would be to permit the revisional authority to trench upon the powers of the primary authority under section 18 of the Act, that too, beyond the period of limitation as prescribed under the said section 18. To reinforce his arguments on the distinct powers conferred on different authorities by the statute, Dr. To reinforce his arguments on the distinct powers conferred on different authorities by the statute, Dr. Saraf also places reliance in Commissioner of Income-tax v. Amitabh Bachcten reported in [2016] 384 ITR 200 (SC) : [2016] 11 SCC 748, for the proposition that having regard to the provisions under sections 18, 36 and 37 of the Act, different shades of powers conferred on different authorities has to be exercised within the areas specifically outlined by the Act. The exercise of power under one provision cannot trench upon the power available under another provision of the Act. In the case in hand, as contended, the power exercised by the DCT was apparently the power statutorily conferred on the assessing authority. The exercise of suo motu revisional power under section 36(1) of the Act was illegal and necessarily forbidden. Lastly, no power is vested in the revisional authority to issue fresh order of assessment on its own, save and except, making a direction to the assessing authority to do the needful. In this context, reliance is placed in Shan-lair Construction Co. v. Additional Commissioner of Commercial Taxes, Belgaum Zone, Belgaum of the Karnataka High Court, reported in [2001] 124 STC 265 (Kani), which has held that it is wholly impermissible for the revisional authority to step into the shoes of the assessing officer and to redo the assessment or pass a fresh assessment order. On the above count, the notice of demand dated July 18, 2011 and that of the order of the Board of Revenue deleting the direction of the revisional authority whereby the assessing authority was made to revise the assessment order as well as the order that the assessment made be deemed to be the assessment of the revisional authority, are assailed as being illegal and contrary to law. 9. Mr. D. Saikia, learned Advocate General (Acting), Assam, makes limited submissions on facts and more on points of law. Mr. Saikia contends that neither the revisional authority had exceeded his jurisdiction nor the Board of Revenue erred in reaching its decision. 9. Mr. D. Saikia, learned Advocate General (Acting), Assam, makes limited submissions on facts and more on points of law. Mr. Saikia contends that neither the revisional authority had exceeded his jurisdiction nor the Board of Revenue erred in reaching its decision. Subject to compliance of the twin conditions for exercise of jurisdiction under section 36(1) of the Act, it is contended that after giving the dealer an opportunity of being heard and after making or causing to be made an enquiry, power vests with the revisional authority to pass an order enhancing or modifying the assessment of tax or cancelling an assessment order and directing issuance of a fresh order. According to Mr. Saikia, the present case does not involve rectification of any arithmetical error or mistake of a factual nature bringing in the applicability of section 37 of the Act. It is a case involving correction of an error which has evidently, occasioned loss of revenue. It is submitted that omission to avail the corrective powers under sections 18 and 37 of the Act cannot denude exercise of powers under section 36 in the facts and circumstances of the present case. In this regard, reliance is placed in Eastern Enterprises v. State of Assam, rendered by a Single Bench of this court and reported in [2007] 7 VST 417 (Gauhati) : [2005] 2 GLT 35. Further submission is that the original assessment order is ex-facie erroneous insofar as it is prejudicial to the interest of the Revenue and the proceeding that had been initiated by the assessing authority for rectification got lost in the way. No conclusion was reached and the apparent error in the assessment order and prejudice caused to the interest of Revenue remained inconclusive. The provisions under the Act do not vest in the Revenue any specific power to question an order of assessment by means of an appeal. Under the circumstances, the revisional authority after having examined the records and having considered that the original assessment order passed by the assessing authority is hit by the twin conditions as appearing in section 36(1) of the Act, was legally justified in taking up the proceedings suo motu and passing the order dated July 10, 2011. Mr. Under the circumstances, the revisional authority after having examined the records and having considered that the original assessment order passed by the assessing authority is hit by the twin conditions as appearing in section 36(1) of the Act, was legally justified in taking up the proceedings suo motu and passing the order dated July 10, 2011. Mr. Saikia in order to explain the circumstances when an order can be termed as "erroneous" and what is meant by the phrase "prejudicial to the interests of the Revenue", relies heavily upon the case in Malabar Industrial Co. Ltd. v. Commissioner of Income-tax, Kerala State reported in [2000] 243 ITR 83 (SC) : [2000] 2 SCC 718 and in the Full Bench decision of this court in Commissioner of Income-tax, Gauhati-1 v. Jazvahar Bhattacharjee reported in [2012] 48 VST 214 (Gauhati) [FB] : [2012] 341 ITR 434 (Gauhati) [FB]. 10. Rival submissions have received our attention and consideration. At the outset we would clarify that the rectification of mistakes in the original assessment order, as put in motion and concluded by the DCT, is definitely not for rectification of any arithmetical error or mistake of a factual nature within the meaning of section 37 of the Act. The proceeding under section 37 that had been initiated by the assessing officer with the notice dated May 26, 2009 did not proceed at all. It appeared to have been abandoned and no reason is found on record. The only plausible explanation would be that having regard to the contours of section 37 with its limited scope for making rectification which is confined to rectifying any arithmetical mistake or other mistake of a factual nature apparent from the record of the case, the said proceeding was cut short. Apparently, the short-coming in the assessment order dated July 5, 2007 was in respect of the percentum of deduction allowed in excess, contrary to the provisions under section 8(3)(iv)(b) of the Act. The exercise so contemplated was not certainly one falling under section 37 of the Act. Under section 18 power vests with the assessing officer, if he has reason to believe, to initiate proceedings for reassessment if any of the conditions as appearing thereto are found to be present, which includes exemption or deduction or relief that has been wrongly allowed or allowed in excess. Under section 18 power vests with the assessing officer, if he has reason to believe, to initiate proceedings for reassessment if any of the conditions as appearing thereto are found to be present, which includes exemption or deduction or relief that has been wrongly allowed or allowed in excess. No proceeding under section 18 was drawn and the incorrect claim made by the petitioner-company for deduction and which had been allowed by the assessment order dated July 5, 2007 remained undisturbed, albeit beyond what was allowable under the statute. In this context it must be borne in mind that the Act does not vest in the Revenue any specific power to question an order of assessment by means of an appeal. Corrective order was passed by reverting to the only possible mode available to the revisional authority under section 36(1) of the Act. Recourse to the said provision and satisfaction derived to the existence of the conditions precedent in section 36(1) justifying the impugned order dated July 10, 2011 is the critical issue for determination. 11. In Amitabh Bachchan [2016] 384 ITR 200 (SC) : [2016] 11 SCC 748, although the facts in issue was distinct to the present one, the Supreme Court held that the statute which conferred different shades of power on different authorities, the same are to be exercised within the areas specifically delineated by the Act. Trenching of powers is not permissible. The power and jurisdiction of the Revenue to deal with a concluded assessment has to be understood in the context of the provisions of the relevant sections. Applying the ratio to the present case, the provision under section 37 of the Act is not applicable proprio vigore. Power under section 18 of the Act was not put in motion to reopen the concluded assessment. It was revised under section 36(1) of the Act, which power vested with the revisional authority. There can be no question of trenching of power in the present exercise. The arguments advanced on this point by Dr. Saraf do not hold any water. 12. Indeed, the basic precondition for exercise of jurisdiction under section 36(1) is the conjoint presence of the twin conditions in the concluded order of assessment, that the same is erroneous and prejudicial to the interest of the Revenue. The arguments advanced on this point by Dr. Saraf do not hold any water. 12. Indeed, the basic precondition for exercise of jurisdiction under section 36(1) is the conjoint presence of the twin conditions in the concluded order of assessment, that the same is erroneous and prejudicial to the interest of the Revenue. It is clarified that the present case do not involve any dispute on non-observance of the principles of natural justice. The contours of section 36(1) certainly do not take within its fold the power to correct each and every type of mistake or error caused by the assessing officer. First, it has to be an order rendered by an incorrect assumption of facts or on an incorrect application of law or without applying the principles of natural justice or without application of mind, so as to satisfy the requirement of the order being "erroneous". Second, the phrase "prejudicial to the interest of the Revenue", though not defined in the Act, cannot be given a narrow interpretation. To be borne in mind, the scheme of the Act is to levy and collect tax in accordance with the provisions of the Act, which is a solemn task entrusted to the Revenue. If due to an erroneous order of the assessing officer, the Revenue is losing tax lawfully payable by a dealer or person, it will certainly be prejudicial to the interest of the Revenue. On this, we take strength from the case in Malabar Industrial Co. Ltd. [2000] 243 ITR 83 (SC) : [2000] 2 SCC 718. 13. Two Division Bench decisions of this court, in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449 and in Commissioner of Income-tax v. Daga Entrade P. Ltd. reported in [2010] 327 ITR 467 (Gauhati), were the subject-matter before the Full Bench in Commissioner of Income-tax, Gauhati-1 v. Jawahar Bhattacharjee [2012] 48 VST 214 (Gauhati) [FB] : [2012] 341 ITR 434 (Gauhati) [FB]. The matter was referred to the Full Bench for resolving the conflict in the said two cases. The matter was referred to the Full Bench for resolving the conflict in the said two cases. Whereas in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449, a Division Bench held that an erroneous order would be one which is plainly contrary to law and the error must pertain to one of jurisdiction, another Division Bench in Daga Entrade [2010] 327 ITR 467 (Gauhati) held that the suo motu revisional power under section 263 of Income-tax Act, 1961 (pari materia to section 36 of the AGST Act) need not be confined to orders passed in error of jurisdiction and interference can be made in a situation where relevant materials have been ignored at the time of making of assessment, resulting in an erroneous order. The Full Bench, on an elaborate examination of the facts in issue, held that the expression "jurisdictional error" used in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449 was made in a wider sense and not in a narrow sense. The Full bench also noticed that in Santalal Mehendi Ratta (HUF) [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197, this court had examined the amplitude of the power of the revisional authority under section 36 of the AGST Act, 1993. In Santalal [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197 it was held that judicial opinion was unanimous that the expression as appearing in section 36 must be confined to jurisdictional errors, otherwise, there would be no distinction between the different aspects of the corrective power conferred by the provisions of the Act for application in different situation. Similar judicial pronouncements of this court, akin to Santalal [2006] 143 STC 511 (Gauhati) : [2002] 1 GLR 197, was noticed and the Full Bench held that the expression "jurisdictional error" cannot be understood in narrow sense. Reliance was also placed in the Supreme Court decision in Malabar Industrial Co. Ltd. [2000] 243 ITR 83 (SC) : [2000] 2 SCC 718, which explained the pre-requisites for exercise of suo motu revisional jurisdiction. The Full Bench held that Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449, read as a whole, does not exclude error in assessment order, by ignoring relevant material. Ltd. [2000] 243 ITR 83 (SC) : [2000] 2 SCC 718, which explained the pre-requisites for exercise of suo motu revisional jurisdiction. The Full Bench held that Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449, read as a whole, does not exclude error in assessment order, by ignoring relevant material. The observation made in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449 has to be read in the context of the entire judgment and such observation made during the course of reasoning in the judgment should not be divorced from the context in which it was used. The Full Bench observed that if this principle is kept in mind, no conflict appears in the view taken in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449 and Daga Entrade [2010] 327 ITR 467 (Gauhati). While holding that Daga Entrade [2010] 327 ITR 467 (Gauhati) lays down correct law, it was also held that the same was not in conflict with the earlier order of this court in Rajendra Singh [1990] 79 STC 10 (Gauhati) : [1990] 1 GLR 449. In conclusion, the Full Bench held that jurisdiction under section 263 of the Income-tax Act, 1961 (pari-materia to section 36) can be exercised whenever it is found that the order of assessment was erroneous and prejudicial to the interest of Revenue, so much so, that it was passed on wrong assumption of facts, on incorrect application of law, without due application of mind or without following the principles of natural justice. These facets are not beyond the scope of the revisional powers. 14. In the case in hand it is now to be seen whether any of the aforesaid deficiencies, as legally recognized, were present in the original order of assessment dated July 5, 2007, thereby justifying recourse made to section 36 of the Act. Section 8(3)(iv)(b) of the Act read with rule 14(1)(b) of the Rules limits the percentage of deduction, as specified in Schedule VI appended to the Act, to not more than 25 per cent. There is no dispute that the amount of deduction claimed and allowed in the assessment order dated July 5, 2007 was more than the statutory limit of 25 per cent. There is no dispute that the amount of deduction claimed and allowed in the assessment order dated July 5, 2007 was more than the statutory limit of 25 per cent. The contents of the show-cause notice dated June 17, 2011 issued by the DCT, resulting in the final order dated July 10, 2011, both reproduced above, leaves no room for doubt that the assessing authority while passing the assessment order dated July 5, 2007 had proceeded by resorting to an incorrect application of the statutory provisions of the Act, thereby allowing deduction to more than 25 per cent. This act also vindicates absence of due application of mind on the part of the assessing officer. Ex-facie, one both the counts above, the assessment order dated July 5, 2007 is erroneous. For the fact that the Revenue lost tax lawfully payable by the petitioner-company, the said erroneous order certainly was prejudicial to the interests of the Revenue. In the light of the discussions and the reasons alluded to above, we are of the considered opinion that the present is a fit case for exercise of suo motu revisional power by the DCT under section 36(1) of the Act. We find no good grounds to disturb the order of the revisional authority dated July 10, 2011 and to the notice of demand dated July 18, 2011. In the same breath, no interference is made with the order of the Board of Revenue. The present revision petition fails and is accordingly dismissed, however, without any order as to cost.