Ujjal Bhuyan, J 1. This writ appeal has been filed by the Commissioner of Taxes, Assam, as the appellant, against the judgment and order dated 05.06.2014, passed by the learned Single Judge, allowing WP(C) No. 3101/2000, filed by the respondents. 2. Appellant was the third respondent in the writ petition. Writ petition was filed by the respondents challenging cancellation of eligibility certificate, which was allowed by the writ court by quashing the impugned orders of cancellation. 3. Facts of the case may be briefly noted. Respondent No. 1 i.e., Megha Assam Coal Mines (India) Ltd. had set up a new industrial unit for manufacture of washed clean coal from raw coal, medium coal and lump coal. In such process, the ash content of coal would be reduced from 25% to 5%. It may be stated that Govt. of Assam had announced an industrial policy in the year 1991, giving incentives to new industries to be established within the State of Assam after 01.04.1991. In terms of the industrial policy, the new industrial units were to be granted reliefs by way of sales tax exemption etc. on the sale of finished products manufactured in eligible industrial units as well as on purchase of raw materials for a period of 7 years. In terms of the said industrial policy, eligibility certificate for such incentives was to be issued to the eligible industrial units by the Industries Department, Government of Assam. To attain eligibility, an industrial unit was required to fulfill various conditions, as laid down in the industrial policy. To give effect to the industrial policy, the Govt. of Assam issued notification dated 16.08.1995 framing a scheme, called 'Assam Industries (Sales Tax Concessions) Scheme, 1995' ('the 1995 Scheme' hereafter) granting sales tax exemption to the eligible industrial units for a period of 7 years on the purchase of raw materials by the eligible industrial units and also on the sale of the finished products manufactured in such eligible units. As noticed above, respondent No. 1 had set up a new industrial unit for manufacture of washed clean coal in terms of the 1995 Scheme. Respondent No. 1 submitted application for grant of eligibility certificate. An enquiry was conducted by the Industries Department on the application filed by the respondent No. 1. Thereafter, eligibility certificate was issued to the respondent No. 1 on 31.03.1998 by the Industries Department, Govt. of Assam. Respondent No. 1 submitted application for grant of eligibility certificate. An enquiry was conducted by the Industries Department on the application filed by the respondent No. 1. Thereafter, eligibility certificate was issued to the respondent No. 1 on 31.03.1998 by the Industries Department, Govt. of Assam. It was stated that commercial production commenced from 05.02.1996. The finished product was washed clean coal and the raw materials used were raw coal, lump coal and medium coal. The eligibility certificate was valid from 05.02.1996 to 04.02.2003 i.e., for a period of 7 years. 4. Following the eligibility certificate issued by the Industries Department, the Sales Tax Department issued the certificate of authorization to respondent No. 1. 5. General Manager, District Industries and Commerce Centre, Kamrup, Guwahati issued show cause notice to respondent No. 1 on 28.03.2000, calling upon the respondent No. 1 to show cause as to why the eligibility certificate issued should not be cancelled. It was alleged that no manufacturing process was involved in the production of washed clean coal from ordinary coal. It was also alleged that respondent No. 1 did not install any plant and machinery to enable it to obtain eligibility certificate. Respondent No. 1 submitted reply dated 07.04.2000 contending that in the processing of washed clean coal from ordinary coal, a manufacturing process is undertaken and washed clean coal has a distinct identity and commercial use. Allegation of non-installation of plant and machinery was denied. It was pointed out that all these aspects were gone into at the time of conducting inquiry before grant of eligibility certificate. 6. General Manager, District Industries and Commerce Centre, Kamrup, Guwahati passed an order dated 03.06.2000 rejecting the reply submitted by respondent No. 1 and cancelled the eligibility certificate dated 31.03.1998 from the date of issue. Consequential formal order was issued by the said General Manager on 05.06.2000. 7. Aggrieved, respondent No. 1 alongwith one of its Directors approached this Court by filing WP(C) No. 3101/2000, challenging the legality and validity of the aforesaid cancellation orders dated 03.06.2000 and 05.06.2000. Writ petition was contested by the third respondent i.e., Commissioner of Taxes by filing affidavit. 8. A Single Bench of this Court, by the judgment and order dated 05.06.2004, allowed the writ petition by quashing the orders of cancellation. 9. Hence, this appeal. Heard Mr. M Nath, learned State Counsel appearing for the appellant and Dr. Writ petition was contested by the third respondent i.e., Commissioner of Taxes by filing affidavit. 8. A Single Bench of this Court, by the judgment and order dated 05.06.2004, allowed the writ petition by quashing the orders of cancellation. 9. Hence, this appeal. Heard Mr. M Nath, learned State Counsel appearing for the appellant and Dr. AK Saraf, learned Senior Counsel for the respondents. 10. Mr. Nath, learned counsel for the appellant submits that the eligibility conditions prescribed under the industrial policy of 1991 and the 1995 Scheme were not complied with by respondent No. 1. Respondent No. 1 was therefore not an eligible industrial unit under the policy as well as under the Scheme, not entitled to the benefits granted thereunder. Eligibility certificate was issued on the basis of a report given by the Senior Superintendent of Taxes, in-charge Deputy Commissioner of Taxes, Guwahati Zone-C, who did not have the jurisdiction to issue such report. It was the Deputy Commissioner of Taxes, Guwahati Zone-A who had the jurisdiction to issue such report. Lastly, he submits that in the process of conversion of ordinary coal into washed clean coal, no manufacturing process takes place and since no manufacturing process takes place, respondent No. 1 would not be entitled to the benefits under the policy as well as under the Scheme. Therefore, eligibility certificate was rightly cancelled. Learned Single Judge had erred in overlooking the aforesaid aspects and as such judgment of the learned Single Judge should be set aside. He has also referred to and relied upon a Division Bench Judgment of this Court in Deepak Kumar Poddar Vs. State of Assam, (2010) 6 GLR 835 wherein it has been held that conversion of raw mustard oil into mustard oil did not involve manufacturing. 11. On the other hand, Dr. Saraf, learned counsel for the respondents raises a preliminary objection as to the maintainability of the writ appeal. He submits that the impugned orders of cancellation of eligibility certificate were issued by the Industries Department, Govt. of Assam, which was interfered with by the learned Single Judge. Writ appeal has been preferred solely by the Commissioner of Taxes, Assam. Sales Tax Department or the Commissioner of Taxes have no role either in the grant of eligibility certificate or in the cancellation of such certificate. Therefore, the appeal ought to have been filed by the State represented by the Industries Department. Writ appeal has been preferred solely by the Commissioner of Taxes, Assam. Sales Tax Department or the Commissioner of Taxes have no role either in the grant of eligibility certificate or in the cancellation of such certificate. Therefore, the appeal ought to have been filed by the State represented by the Industries Department. Appeal filed at the instance of the Commissioner of Taxes is not maintainable. Regarding jurisdictional competence of the authority who submitted the report on the basis of which the eligibility certificate was issued, he submits that this was not a ground taken in the show-cause notice or formed the basis for cancellation of the eligiblity certificate. Therefore, such submission is wholly untenable. On merits, learned Senior Counsel submits that the view taken by the learned Single Judge is the correct view and no interference is called for. Eligibility certificate was cancelled on grounds which were not mentioned in the show cause notice. Further, the question as to whether the particular activity involves manufacturing process would have to be examined in the light of the definition of 'manufacture', as given in the Assam General Sales Tax Act, 1993 ('the 1993 Act' hereafter). Definition of manufacture under the 1993 Act is a wide one encompassing a wide range of activities, which would include conversion of raw coal, lump coal or medium coal into washed clean coal. 12. In his reply, Mr. Nath submits that an application has been filed, which has been registered as Misc. Case No. 980/2012, for impleadment of State of Assam in the Industries Department and General Manager, District Industries and Commerce Centre, Kamrup, Guwahati as appellants in the present writ appeal. Therefore, Court may implead the said two parties as appellants even at this stage and decide the appeal on the substantive issue. 13. Submissions made by learned counsel for the parties have received the due consideration of the Court. 14. After hearing learned counsel for the parties, we are of the opinion that the following issues arise for consideration in this appeal:- Whether the writ appeal is maintainable in its present form? Whether cancellation of the eligibility certificate was justified? Whether the process of conversion of raw coal, lump coal or medium coal into washed clean coal involves a manufacturing process? Maintainability of the writ appeal As already noticed above, the eligibility certificate was issued by the Industries Department, Govt. of Assam. Whether cancellation of the eligibility certificate was justified? Whether the process of conversion of raw coal, lump coal or medium coal into washed clean coal involves a manufacturing process? Maintainability of the writ appeal As already noticed above, the eligibility certificate was issued by the Industries Department, Govt. of Assam. The impugned orders of cancellation of eligibility certificate dated 03.06.2000 and 05.06.2000 were issued by the General Manager, District Industries and Commerce Centre, Kamrup, Guwahati. Learned Single Judge has quashed the aforesaid orders of cancellation in the writ petition. However, writ appeal has been filed only by the Commissioner of Taxes, Assam. Neither the State of Assam in the Industries Department nor the General Manager, District Industries and Commerce Centre, Kamrup, Guwahati has filed the appeal. 15. Grant of eligibility certificate and cancellation of eligibility certificate is within the domain of the Industries Department and not the Sales Tax Department. In Vadilal Chemicals Ltd. Vs. State of AP & Ors., (2005) 6 SCC 292 , the Apex Court had held that the eligibility certificates were issued by the Department of Industries and Commerce and could not be cancelled by the Sales Tax authority. Department of Industries was in the best position to construe its own order. The State, which is represented by many departments, can only speak with one voice. Having regard to the exemption scheme, the view expressed by the Department of Industries must be taken to be the voice of the State. This decision was approvingly referred to in the subsequent decision of the Apex Court in Pondicherry State Coop. Consumer Federation Ltd. Vs. Union Territory of Pondicherry, reported in (2008) 1 SCC 206 . Thus, on a careful consideration of the above decisions, it becomes evident that in matters of eligibility certificates, the State must speak through the Industries Department. Therefore, in the factual context of the present case, it is the Industries Department which is the aggrieved party and not the Sales Tax Department. 16. On the other hand, Article 300 of the Constitution of India provides that the Govt. of India may sue or be sued by the name of Union of India and the Govt. of a State may sue or be sued by the name of the State. Section 79 of the Civil Procedure Code deals with suits by or against the Govt. of India may sue or be sued by the name of Union of India and the Govt. of a State may sue or be sued by the name of the State. Section 79 of the Civil Procedure Code deals with suits by or against the Govt. It says that in a suit by or against the Govt., the authority to be named as plaintiff or defendant, as the case may be, in the case of the Central Govt., the Union of India and in the case of the State Govt., the State. 17. The aforesaid provisions were examined by the Apex Court in (2003) 3 SCC 472 (Chief Conservator of Forests, Govt. of AP Vs. Collector & Ors.). That was a case where there was dispute between the departments of the Govt. regarding title of the lands in question. Commissioner of Survey, Settlement and Land Records took the view that those were patta lands and upheld the decision of the Collector. The dispute arose in the backdrop of land acquisition proceedings. At that stage, the Chief Conservator of Forest moved a writ petition before the High Court. In the above back drop, the Apex Court held that in a lis dealing with the property of a State, there can be no dispute that the State is a necessary party and should be impleaded as provided in Article 300 of the Constitution and Section 79 of the Civil Procedure Code. It was held that in the absence of the State, the suit will be bad for non-joinder of necessary party. It is not merely a procedural formality, but is essentially a matter of substance and of considerable significance. Every post in the hierarchy of posts in the Govt. set-up, from the lowest to the highest, is not recognized as a juristic person nor can the State be treated as represented when a suit/proceeding is in the name of such offices/posts or the officers holding such posts. Therefore, in the absence of the State in the array of parties, the cause will be defeated for non-joinder of necessary party to the lis. 18. Having regard to the above, we may now turn our attention to the application filed by the State and the General Manager for adding them as appellants in the writ appeal. It is seen that the said application was filed six years after filing of the appeal. 18. Having regard to the above, we may now turn our attention to the application filed by the State and the General Manager for adding them as appellants in the writ appeal. It is seen that the said application was filed six years after filing of the appeal. Writ appeal was filed on 23.05.2006, whereas the application was filed on 31.03.2012. On 27.09.2012, a Division Bench of this Court though heard arguments on the preliminary issue regarding impleadment of the State of Assam, took the view that having regard to the year of registration of the appeal and the litigational background, the appeal should be heard simultaneously on merit as well, thus declining to implead the State as appellant. 19. In view of the legal position as discussed above, we are of the considered opinion that the application filed for impleadment of the State of Assam and the General Manager as appellants to the writ appeal is belated and cannot be accepted. We may look at it from another angle. Had the State and the General Manager filed an appeal after six years, would the same not have been barred by limitation? The answer would obviously be in the affirmative. Moreover, the affidavit in support of the said application is sworn by the General Manager. Nothing has been placed on record to show that the said General Manager was authorized by the State to file an application on its behalf seeking impleadment as appellant. 20. Thus, from a dispassionate consideration of the above, it is clear and evident that the writ appeal filed at the instance of the Commissioner of Taxes, Assam is not maintainable. 21. In view of the finding arrived at above, the writ appeal can be dismissed without adverting to the other issues involved. However, keeping in mind the observation of this Court in the order dated 27.09.2012, we deem it appropriate not to confine the adjudication of the appeal to the above issue only. Whether cancellation of eligibility certificate was justified 22. As already noticed above, the show-cause notice was issued to respondent No.1 for cancellation of eligibility certificate on two grounds. Firstly, no manufacturing process was involved in the conversion of raw coal etc. into washed clean coal. Secondly, respondent No.1 did not install any plant and machinery for the purpose of manufacturing washed clean coal. As already noticed above, the show-cause notice was issued to respondent No.1 for cancellation of eligibility certificate on two grounds. Firstly, no manufacturing process was involved in the conversion of raw coal etc. into washed clean coal. Secondly, respondent No.1 did not install any plant and machinery for the purpose of manufacturing washed clean coal. In the cancellation order dated 03-06-2000, after noticing that respondent No.1 was granted eligibility certificate for manufacture of washed clean coal from raw coal, lump coal and medium coal, it was held that there was no substantial difference between the raw material and the finished product. Both were same i.e., coal. Therefore, no manufacturing process took place. Since there was no manufacture, respondent No.1 was not an eligible unit entitled to the benefits under the policy and the Scheme. Eligibility certificate was wrongly issued. It was also held that no factory shed or office room was found in the premises of respondent No.1 to suggest any manufacturing activity. As such, the eligibility certificate was cancelled from the date of issue. 23. Part-III of the 1995 Scheme provides for cancellation of eligibility certificate as well as certificate of authorization for violation of or for non-compliance with any of the conditions laid down in the Scheme. A reading of part-III of the Scheme would indicate that an eligibility certificate can be cancelled on the following grounds :- (i) Violation of any condition of the eligibility certificate, or (ii) If any information on any of the conditions of the eligibility certificate is found false at any time after the eligibility certificate has been issued, or (iii) Failure on the part of the holder of the certificate of authorization, to comply with any condition laid down in the certificate of authorization, or (iv) Failure to maintain the account of declaration form, or (v) Failure to furnish any information required by the Assessing Officer with regard to implementation of the Scheme. 24. We have already noticed the two grounds for cancellation of the eligibility certificate. Coming to the second ground of cancellation, learned Single Judge recorded the following finding:- “86. Moreover, not only the first, but even the second ground taken in the show cause notice that there are no plants and machinery installed also does not, one must remember, come within the purview of false information. Coming to the second ground of cancellation, learned Single Judge recorded the following finding:- “86. Moreover, not only the first, but even the second ground taken in the show cause notice that there are no plants and machinery installed also does not, one must remember, come within the purview of false information. In the present case, a perusal of the application for issuance of the Eligibility Certificate would reveal that the writ petitioners had not specified that any plant or machinery would be installed. Therefore, not finding of any plant and machinery at the site of the industrial Unit could not have been made a ground for cancellation of the Eligibility Certificate. 87. Admittedly, the processing Unit did not involve any plant and machinery. It has been submitted by the petitioners that the process of manufacturing of washed clean coal is undertaken manually thereby creating an opportunity for wide scale employment of local labour. That being the position, it is difficult to understand as to how the authorities concerned expected to find any plant or machinery at the said site. It is nobody's case that industrial activity cannot be undertaken manually. The scheme with which we are concerned speaks about granting of Eligibility Certificate to an industrial Unit. It does not specify that the industrial Unit must be operated mechanically or with the aid of power. Therefore, this aspect of the impugned order does not hold water.” 25. We agree with the view taken by the learned Single Judge. The above could not have been a ground for cancellation of the eligibility certificate. As pointed out by the Apex Court in Pondicherry State Cooperative Consumer Federation Limited (supra), since exemption was granted with open eyes to the particular industry, the State cannot be allowed to turn around later on and take a stance that the assessee was not entitled to the exemption on the ground that it did not manufacture any goods. As pointed out by the Apex Court in Pondicherry State Cooperative Consumer Federation Limited (supra), since exemption was granted with open eyes to the particular industry, the State cannot be allowed to turn around later on and take a stance that the assessee was not entitled to the exemption on the ground that it did not manufacture any goods. Regarding termination of eligibility certificate under clause-12 of the Assam Industries (Tax Exemption for Pipeline Units) Order, 2005, which deals with similar situation, a Division Bench of this Court in the case of Sunil Kumar Taparia -Vs- State of Assam, reported in 2013 (1) GLR 14 held that termination of eligibility certificate on change of opinion as to the eligibility of the certificate holder to get the benefit would be clearly ultra-vires the power conferred under clause-12 of the 2005 Order. Question which fell for consideration in that case was as to whether eligibility certificate once granted on formation of a bonafide opinion on a debatable issue can be cancelled by changing the opinion. The question was answered in the negative. Following the above decision, a Division Bench of this Court in JAI CHEMICAL INDUSTRIES -VS- STATE OF ASSAM, (2013) 1 GLR 718 held that mere change of opinion at a belated stage cannot be a ground for declining eligibility certificate. It has further been held that once the Department has taken a view to grant eligibility for exemption under the Scheme, which is a possible view, the same cannot be changed on mere change of opinion. 26. Coming to the present case, it is clear from what has been discussed above that it is not a case of obtaining eligibility certificate by fraud or by furnishing of wrong information. Nothing has been pointed out regarding violation of any of the conditions mentioned in the eligibility certificate. It is quite clear that the eligibility certificate granted to respondent No.1 was cancelled because of change of opinion as to the eligibility of respondent No.1 to get the benefit. This is not permissible. The issue as to whether activity of respondent No.1 in conversion of raw coal, lump coal and medium coal into washed clean coal amounts to manufacture in the context of the wide and liberal definition of “manufacture” under Section 2 (22) of the 1993 Act and in view of Deepak Kumar Poddar (supra) is a debatable issue. The issue as to whether activity of respondent No.1 in conversion of raw coal, lump coal and medium coal into washed clean coal amounts to manufacture in the context of the wide and liberal definition of “manufacture” under Section 2 (22) of the 1993 Act and in view of Deepak Kumar Poddar (supra) is a debatable issue. As per opinion earlier formed by the Industries Department, respondent No.1 was eligible which is certainly a possible view. By a subsequent change of view, eligibility cannot be cancelled. 27. Therefore, in our considered opinion, cancellation of the eligibility certificates was not correct and learned Single Judge was justified in quashing the cancellation orders dated 03-06-2000 and 05-06-2000. 28. In view of our finding on issue Nos. 1 and 2 above, it is not necessary for us to go into the third issue i.e. the question as to whether activity of respondent No.1 amounts to manufacture or not. 29. For the reasons indicated above, we do not find any merit in the writ appeal which is accordingly dismissed. No cost.