Honble CHOPRA, J.—These three writ petitions involve common questions of law, although facts are slightly different, and therefore, they were heard together and are being disposed of by a common Order/Judgment. (2) FACTS OF M/S. ARYAN ZINC PRODUCTS CASE; The case of the petitioner is that it has been granted eligibility certificate for exemption (Annexure-2) dated 9.6.1988 under the Incentive Scheme, 1987 which was notified vide Notification dated 23.5.1987 issued under the provisions of Rajasthan Sales Tax Act and the Central Sales Tax Act. This eligibility certificate which was granted by the Screening Committee was renewed upto 7.6.1990. The petitioner has fully availed the said exemption to the maximum extent of the quantum of the incentives as per the eligibility certificate granted to it. The only contention raised by the petitioner is that the Govt. of Rajasthan has now issued a clarification vide. S.O./F.4 (92) FDGr. IV/91-49 dated 7.9.1991 whereby an Explanation has been added to Note-6 in Annexure-C of the said Incentive Scheme, 1987 and it has been clarified that since the inception of the principal notification as amended from time to time, in case of expan-sion/diversification only the sales of goods of expanded production or diversified production, as the case may be shall be entitled to incentive provided for. In other words, the incentives will be, available only on the turnover which is proportionate to the expansion or diversification investment made and the sale tax exemption which has been claimed over the remaining turn over will be liable to tax and interest. Aggrieved against this clarification dated 7.9.1991, the petitioner has filed this writ petition challenging the retrospective operation of that Notification whereby an explanation had been added to Note-6 in Annexure-C of the said Incentive Scheme, 1987. (3) FACTS OF M/S. KANSAL UDHYOG CASE: The petitioner firm is a Stainless Steel re-rolling Mill, which has been granted provisional eligibility certificate (Ex. R.2) dated 25.11.1991 under the Incentive Scheme, 1987 by the Screening Committee. This eligibility certificate has been renewed upto 24.11.1992. It is alleged that while issuing this provisional eligibility certificate, a condition has been imposed that the Unit is eligible for incentive for the sale of goods of expanded production only. According to the petitioner, vide notification dated 7.9.1991, the aforesaid explanation has been added to Note- 6 in Annexure-C of the said Incentive Scheme, 1987. It is alleged that while issuing this provisional eligibility certificate, a condition has been imposed that the Unit is eligible for incentive for the sale of goods of expanded production only. According to the petitioner, vide notification dated 7.9.1991, the aforesaid explanation has been added to Note- 6 in Annexure-C of the said Incentive Scheme, 1987. It therefore, challenges the prospectively of this explanation by this writ petition. (4) In this case, there is no dispute about the eligible capital investment. The contention of the petitioner firm is that it is entitled to avail the incentives to the extent of eligible investment and the same cannot be restricted to the turn over of the product making it proportionate to the expansion investment and, therefore, it has been prayed that the explanation added to Note-6 in Annexure-C of the said Incentive Scheme, 1987 be struck down. (5) FACTS OF M/S. MOHNOT STAINLESS STEEL INDUSTRIES CASE: The petitioner-firm is also a Stainless Steel Re-rolling Mill. M/s. Kansal Udhyog as also the petitioner-firm earlier filed a writ petition before this Court claiming issuance of Eligibility Certificate and it was only under the orders of this Court that provisional eligibility Certificates were issued to them. Earlier, Stainless Steel Re-rolling Mills were included in the list of prohibited Industries which were not entitled to Sales Tax incentives. When that prohibition was removed, this Court passed an order that provisional Eligibility Certificates be issued to the petitioners. Against that order passed by a learned single Judge of this Court, a special appeal has been filed and that is still pending. Be that as it may, in this writ petition, the petitioner has claimed that he has been issued provisional eligibility certificate treating its eligible investment as Rs. 8,11,939/- as against the actual eligible investment claimed by the petitioner amounting to Rs. 20,31,778.08P. Thus, in this writ petition, the petitioner has claimed eligibility for the amount which is higher than what has been allowed to it by the Screening Committee. The rest of the contentions raised by the petitioner are the same which have been raised in Kansal Udhyogs case (supra). (6) Separate replies to the writ petitions have been filed on behalf of the respondents in all the three writ petitions. The rest of the contentions raised by the petitioner are the same which have been raised in Kansal Udhyogs case (supra). (6) Separate replies to the writ petitions have been filed on behalf of the respondents in all the three writ petitions. It has been contended that the petitioner firms viz., M/s. Kansal Udhyog and M/s. Mohnot Stainless Steel Industries being Stainless Steel Re-rolling Mills, the Development Commissioner, Small Scale Industries, Govt. of India, New Delhi issued a Notification dated 12.1.1988 whereby these Mills were included in the prohibited category of Mills which were not entitled to any incentives but that embargo was removed in view of the liberalised policy of the Govt. of India vide its Notification dated 16.8.1991. Thus, it has been claimed that between 12.1.1988 and 15.8.1991, both these firms were not entitled to any grant of incentives. According to the respondents, M/s. Mohnot Stainless Industries started its production with effect from 13.3.1988 i.e. after the Govt. Notification dated 12.1.1988 was issued and M/s. Kansal Udhyog also started its production with effect from 1.3.1989 and, therefore, both these firms are not entitled to any incentives being granted to them. However, under the orders of this Court, provisional eligibility certificates were granted to them on the basis of their eligible investment but as the Govt. of Rajasthan has added the aforesaid explanation to Note-6 in Annexure-C of the said Incentives Scheme, 1987, incentives cannot be granted to the petitioners over the total investment. It can only be granted on the eligible investment made by them on their expansion project or diversified project. (7) It may be clarified here that all the three Units have claimed that they have expanded their projects. Thus, the eligibility investment made by them is under the head of expansion and not under the head of diversification. (8) Be that as it may, the contention of the respondents is that when any incentive is granted, it can always be granted under certain conditions, which the authorities sanctioning incentives may deem it proper to attach with the Incentive Scheme. It is just, reasonable and proper that when incentive is granted only in relation to the existing Units as regards their eligible investment, which they have made for expansion of their project or for diversification of their project then incentives should be made available only of that expanded/diversified amount and not on the entire project. It is just, reasonable and proper that when incentive is granted only in relation to the existing Units as regards their eligible investment, which they have made for expansion of their project or for diversification of their project then incentives should be made available only of that expanded/diversified amount and not on the entire project. According to the respondents, M/s. Mohnot Stainless Industries and M/s Kansal Udhyog effected the expansion of their existing Units and they started their commercial production with effect from 13.3.1988 and 1.3.1989 respectively i.e. after the Govt. Notification dated 12.1.1988 was issued and, therefore, they are not eligible to any relief as regards incentives. However, provisional eligibility certificate have been granted to them under the orders of this Court and against the orders passed by a learned single Judge of this Court, a special appeal has been filed and that is still pending. According to the respondents, while issuing provisional eligibility certificates to M/s Mohnot Stainless Industries and M/s Kansal Udhyog, it has been made clear that these Units will be eligible for incentives for the sale of goods of expanded production only. It was further contended that the explanation appended to Note-6 in Annexure-C of the Incentives Scheme, 1987 is retrospective in operation and is perfectly legal and valid. It is in accordance with the settled norms and principle of law and, therefore, it does not deserve to be quashed. (9) Rejoinders have also been filed on behalf of the petitioners in all these three writ petitions and it has been emphasised that in case of a product passing to the finished stage through both the projects, namely old investment project and expansion investment project, it would not be possible to bifurcate value of such goods and to ascertain the value eligible for exemption. It has also been claimed that since the quantum of incentive is fixed on the basis of eligible investment made in the expansion project, there is no reason for restricting the benefit proportionate to the product attributable to the expansion project. In other words, if the incentive is availed at higher value, the assesee would exhaust the incentive earlier and vice versa and, therefore, there is no justification for restricting the benefit in such a proportionate manner. In other words, if the incentive is availed at higher value, the assesee would exhaust the incentive earlier and vice versa and, therefore, there is no justification for restricting the benefit in such a proportionate manner. According to the petitioners, the impugned Notification renders the entire Scheme unworkable and has no rationale nexus behind it and, therefore, it deserves to be quashed. (10) We have heard Mr. Vinit Kothari,the learned counsel appearing for the petitioners, Mr. B.C. Mehta, the learned counsel appearing for the respondents and Mr. L.S. Udawat, the learned Additional Advocate General appearing for the State and have carefully gone through the record of the case. (11) So far as the dispute regarding the quantum of eligible investment is concerned, that has to be decided by the District Screening Committee. This Court cannot go into such disputed questions of facts. It may be stated here that the dispute regarding the quantum of eligible investment has been raised in M/s Mohnot Stainless Steel Industries case (supra). In that case, earlier when the incentives were claimed, it was claimed for Rs. 8,13,579.23P. This amount was later on cut and in its place, an amount of Rs. 20,31,778.08P. was written but the percentage of increase in the fixed capital investment was shown as 57.49% because the fixed capital investment before expansion was Rs. 14,15,127.24P. Thus, when this percentage was not changed, it clearly meant that the eligible investment made by them was only Rs. 8,13,579.23P. as is clear from Annexure-6 filed alongwith the writ petition of M/s. Mohnot Stainless Steel Industries case (supra). However, later a certificate was obtained from a Chartered Accountant and in that certificate, it was claimed that the eligible investment is Rs. 20,05,345.92P. Before that, a claim was made that the eligible investment is Rs 25,53,670/- as is clear from Annexure-3. Thus, the petitioner has been taking contradictory stands so far as the eligible investment is concerned. It appears that alongwith the certificate issued by Shri Kailash Chand Bhansali Chartered Accountant, a statement was filed and in that statement, it was clarified that the fixed capital investment upto 30.6.1988 was Rs. 8,13,579.23P. and the investment after 30.6.1988 was Rs. 12,18,198.85P. and thus, the total comes to Rs. 20,31,778.08P. It appears that alongwith the certificate issued by Shri Kailash Chand Bhansali Chartered Accountant, a statement was filed and in that statement, it was clarified that the fixed capital investment upto 30.6.1988 was Rs. 8,13,579.23P. and the investment after 30.6.1988 was Rs. 12,18,198.85P. and thus, the total comes to Rs. 20,31,778.08P. This statement was furnished by the petitioner firm M/s Mohnot Stainless Steel Industries but in the certificate that has been issued by the concerned Chartered Accountant, this amount has been reduced to Rs. 20,05,345.92P. It is true that the petitioner firm has made several representations to the Screening Committee to revise the amount of eligible investment but it has fallen on deaf ears. It is expected that the District Screening Committee will examine the record to find out the actual eligible capital investment and thereafter, it will issue eligibility certificate accordingly. The District Screening Committee cannot sit over the papers. It must decide the representations submitted by the petitioner-firm. Inaction is no answer to the request made by the petitioner firm and, therefore, so far as this aspect of the matter is concerned, only a direction can be issued to the District Screening Committee to examine the matter afresh and give its decision within a period of two months from today. (12) Having dealt with this aspect of the matter which has been raised in M/s Mohnot Stainless Steel Industries case (supra), now we proceed to examine the most important question that has been raised in these writ petitions, which relates to the addition of an explanation to Note-6 in Annexure-C of the Incentives Scheme, 1987. Explanation added to Note-6 in Annexure-C of the said Incentive Scheme, 1987 reads as under: — "Explanation: — It is clarified that since the inception of the principal notification as amended from time to time, in case of expansion/diver-sification only the sales of goods of expanded production or diversified production, as the case may be, shall be entitled to incentive provided for." It may be stated here that this explanation was added vide Govts notification dated 7.9.1991 and it has been made retrospective in operation. Now, it has to be seen whether such an explanation can be added; whether it is workable and whether it can be made retrospective or prospective in operation? (13) It has been contended by Mr. Now, it has to be seen whether such an explanation can be added; whether it is workable and whether it can be made retrospective or prospective in operation? (13) It has been contended by Mr. B.C. Mehta, the learned counsel appearing for the respondents that it is a case of grant of incentives and while granting incentives, the State Govt. may attach any conditions to the incentives that are to be granted by it. According to him, the State Govt. is not obliged to grant any incentives but in order to achieve faster growth in industrial development of the State or the expansion of the production capacity, if it chosen to grant certain incentives of its own accord and if they are granted, they can be granted with certain conditions attached to them. Incentives cannot be claimed as of right. It is only a mere concession and while granting such concessions, the State Govt. is free to put any condition (s) and, therefore, nobody can raise any objection as to why such an explanation has been added to this Incentives Scheme, 1987. When the Incentives Schemes is only intended to cover the Fixed Capital Investment made on expansion or diversification and it has no concern with the original investment made by a Unit/Factory/Manufacturer/Industry then such an intention of the framers of the Incentive Scheme can be said to be very reasonable and, therefore, making the incentives proportionate to the Fixed Capital Investment made for the purpose of expansion or diversification is neither unjust nor unreasonable nor unworkable. So far as the diversification is concerned, the product which comes out of the diversified project will be a separate product and if it is sold, the sales tax incentives can be safely claimed on the product of diversified project. Mr. Vineet Kothari, the learned counsel for the petitioners also does not object to this submission. If as a result of expansion, certain additional production is brought about by bringing about a change in the process of manufacture, which can be distinguished from the type of production already made and then the sales tax incentive can be claimed about that additional product alone. The difficulty arises when while making expansion,the process of production is not changed but it only results in increasing the quantum of production. The difficulty arises when while making expansion,the process of production is not changed but it only results in increasing the quantum of production. For example, earlier a factory was producing 50 metric tonnes of steel sheets and now, on account of the expansion, it now produces 70 metric tonnes of steel-sheets but the process cannot be separately identified so far as the increased production is concerned because it has to pass through the same process of manufacture and in such circumstances, according to Mr. Kothari, such a scheme becomes unworkable. (14) We are unable to accept this contention raised by Mr. Kothari. If the factory was earlier producing 50 metric tonnes of steel-sheets and now it is producing 70 metric tonnes of steel sheets then in such a case, sales tax incentives can be claimed on the increased percentage of production. It is not very difficult to find out how much was the production when the original Fixed Capital Investment was there and how much it has increased on account of the expansion later on. It has been provided in the Scheme, which came into force with effect from 5.3.1987, that only those Units will be eligible for sale tax incentive on account of the Fixed Capital investment made on the expansion when that Fixed Capital Investment is not less than 25% of the net fixed assets of the existing project. Thus, the FCI which was originally made and the FCI which is made as a result of the expansion has to be quantified separately and before any incentive can be claimed, it has to be proved that it is at least 25% of the original FCI. The matter does not rest there. For availing the sales tax incentive, an applicant is further required to prove that this 25% additional capital investment made under the head expansion has resulted in the increase in the production to the extent of at least 25% of the original capacity. Thus, it is essential for an applicant seeking sales tax incentives to show how much was his original production on the basis of his original Fixed Capital Investment and how much it has been increased on account of the expansion of the Fixed Capital Investment made by him. Thus, it is essential for an applicant seeking sales tax incentives to show how much was his original production on the basis of his original Fixed Capital Investment and how much it has been increased on account of the expansion of the Fixed Capital Investment made by him. (15) While applying for grant of eligibility certificate under the Sales Tax Incentive Scheme, the petitioner firm M/s Mohnot Stainless Steel Industries has filed a certificate obtained from a Chartered Accountant and a statement showing what was the original investment and what was the original production and what has been achieved in the shape of an increase in the original production and how much increase is there in the Fixed Capital Investment after the expansion of the Project. Thus, to restrict the sale tax incentive to the percentage of increase, in the production vis-a-vis the original production is neither unjust nor improper nor unworkable. Simply because the process of production is not changed and only increase in the production is achieved that also does not pose any difficulty in granting incentive on the FCI made for the purpose of expansion. It is true that the incentive is availed on a particular percentage of Fixed Capital Investment and the producer or manufacturer is not allowed to exceed that limit but when the Scheme has not intended to grant any incentive on the original production, it is futile to argue that the production which is made on account of the original Fixed Capital Investment should also be made eligible for the sale tax incentive because if that contention is accepted, it will go against the Scheme itself. This explanation has been added only on 7.9.1991 and not prior to that. Prior to that, the Department itself has assessed M/s Aryan Zinc Product and others on the basis of the total production made by them and the incentive was granted thereon because at the time, when the scheme was promulgated on 5.3.1987, it was not clarified that the incentive that is granted will be available on proportionate production achieved on account of the expanded Fixed Capital Investment. Only a ceiling was fixed as regards the eligibility for the incentive and the petitioners were entitled to exhaust that limit irrespective of the fact whether the incentive is claimed on the proportionate expanded product only or on the entire production. Only a ceiling was fixed as regards the eligibility for the incentive and the petitioners were entitled to exhaust that limit irrespective of the fact whether the incentive is claimed on the proportionate expanded product only or on the entire production. Thus explanation added on 7.9.1991 actually restricts the availability of the incentive to the extent of the proportionate increase in production achieved as a result of the FCI made on the expansion. This was not the original idea and, therefore, those persons who started making FCI on the basis of the earlier Annexure-C appended to the Incentive Scheme, 1987 when the explanation to Note-6 in Annexure-C of the Incentive Scheme was not there, the sales tax of the percentage allowable incentive will be available to them to the extent eligible FCI and it will not be restricted to a proportionate increase in the production based on the FCI made either on expansion or diversification. Such a change in the policy which has been brought about by the State Govt. by adding the aforesaid explanation to Note-6 in Annexure-6 of the Incentive Scheme, 1987 is a policy decision which changes the character of the incentive available and, therefore, it can only be applied prospectively and not retrospectively. In this respect, we may place reliance on a decision of their lordships of the Supreme Court in Mangalore Chemicals & Fertilisers Ltd. vs. Dy. Commr. of Commercial Taxes (1), wherein it has been held that if the conditions prescribed for eligibility were altered by the subsequent notification after the establishment of industry then the conditions prescribed by the subsequent notification will be applicable prospectively. The eligibility earned is not lost. (16) Thus, so far as M/s Aryan Zinc Products is concerned, the eligibility certificate was granted to it when the explanation was not there. It has already exhausted the sale tax incentive granted in its favour and, therefore, this explanation which has been added to Note-6 in Annexure-C of the Incentive Scheme, 1987 vide notification dated 7.9.1991 will be applicable only prospectively and not retrospectively. (17) So far as the other writ petitions filed by M/s Mohnot Stainless Steel Industries and M/s Kansal Udhyog are concerned, it has not been disclosed by them what investment was made by them before 12.1.1988 on the expansion of their project. (17) So far as the other writ petitions filed by M/s Mohnot Stainless Steel Industries and M/s Kansal Udhyog are concerned, it has not been disclosed by them what investment was made by them before 12.1.1988 on the expansion of their project. Even in Mohnot Stainless Steel Industries case, although certain figures have been supplied by them but it has only been stated as to what investment was made before 30.6.1988 and what was made after 30.6. 1988, but it has not been disclosed as to FCI was made prior, to 12.1.88. Be that as it may, these two petitioners who are the manufactures of stainless steel re-rolling were not eligible to any sale tax incentive as per the Govt. Notification dated 12.1.1988 and,therefore, they were not entitled to grant of any eligibility certificate. The principle of promissory estoppel does not apply in their cases. It can only apply to the extent of their investment which has been made by them in their expanded project prior to 12.1.1988 and when that fact has not been disclosed as to what investment was made by them prior to 12.1.1988, the principle of promissory estoppel will not apply in their cases. When the provisional eligibility certificate has been granted to them under the orders of the Court and that certificate has been granted to them after 7.9.1991, on that count also, the principle of promissory estoppel will not apply to their cases. It only applies to the case of M/s Aryan Zinc Products case. (18) In view of the discussion made herein-above, the writ petition filed by M/s Aryan Zinc Product is allowed and it is held that the explanation added to Note-6 in Annexure-C of the Incentive Scheme, 1987 vide Notification dated 7.9.1991 is only prospective in nature and cannot be applied retrospectively and, therefore, the advantages which have been conferred on the petitioner-firm and which have been availed by it cannot be taken away by the authorities. (19) So far as the writ petitions filed by M/s Mohnot Stainless Steel Industries and M/s Kansal Udhyog are concerned,they are allowed in part and it is hereby clarified that this explanation added to Note-6 in Annexure-C of the Incentives Scheme, 1987 will be applicable prospectively and therefore, to that extent, the eligibility certificate granted in their favour is neither illegal nor unjust and they will only be entitled to the sales tax incentives on the increased production achieved by them which is proportionate to their FCI. They have been granted provisional Eligibility Certificates and those Certificates will abide by the result of the special appeals that have been filed by the respondents before this Court. (20) So far as Mohnot Stainless Steel Industries is concerned, it has claimed that its eligible Fixed Capital Investment is Rs. 20,31,778.08P. whereas the provisional eligibility certificate has been granted to it only for the FCI of Rs. 8,13,579.23P. Against that, they have made several representations to the District Screening Committee to increase their eligibility but it has fallen on deaf ears. The District Screening Committee is therefore, directed to decide its representations within a period of two months from today and thereafter to issue provisional eligibility certificate to it according to its eligible fixed capital investment as per Rules. (21) In the facts and circumstances of this case, the parties are left to bear their own costs.