Judgment :- Raju, J. The above writ appeal has been filed against the order of the learned single Judge, dated 13. 1988 made in W.P.No.7753 of 1984, whereunder the writ petition filed by the first respondent before us came to be allowed on the ground that the amended regulation in question cannot be made with retrospective effect. 2. The 1st respondent/Association has filed W.P.No.7753 of 1984 praying for a declaration that explanation III to Regulation No.23 of the Tamil Nadu Water Supply and Drainage Board Regulations, 1972 (hereinafter called as Regulation) as illegal, ultra vires and consequently directing the respondents in the writ petition to consider all the Assistant Draughtsmen (Non-Diploma), who have completed 5 years of service for promotion to the post of Draughtsmen Grade III (Junior Drafting Officer) in the Tamil Nadu Water and Drainage Board (hereinafter referred to as the Board). The relevant and necessary factual details set out hereinafter are beyond controversy. The Tamil Nadu Water Supply and Drainage Board was incorporated under the provisions of the Tamil Nadu Water Supply and Drainage Board Act, 1970 (Tamil Nadu Act 4 of 1971) with effect from 14. 1971. Sec.9 of the Act enables the Board to appoint the Secretary, Chief Engineer, Accounts Officer and other Officers and Staff of the Board, subject to the stipulations contained therein. Sec. 73 empowers the Board to make regulation, by notification not inconsistent with the Act and the rules made thereunder for the purpose of giving effect to the provisions of the Act and more particularly, among other things, providing for the terms and conditions of appointment and service and the scales of pay of officers and servants of the Board including the payment of travelling and daily allowances in respect of journeys undertaken by such officers and servants of the Board as well as the supervision and control over the Acts and proceedings of the officers and servants of the Board and the maintenance of discipline and conduct among the officers and servants of the Board. Sub-sec.(3) of Sec. 73 provided that no regulation or its cancellation or modification shall have effect until the same shall have been approved by the Government. 3. The Tamil Nadu Water Supply and Drainage Board Service Regulations 1972 came to be made in B.P.Ms.No.398, dated 112. 1972 with effect from 14. 1972. Sub-sec.(3) of Sec. 73 provided that no regulation or its cancellation or modification shall have effect until the same shall have been approved by the Government. 3. The Tamil Nadu Water Supply and Drainage Board Service Regulations 1972 came to be made in B.P.Ms.No.398, dated 112. 1972 with effect from 14. 1972. Under Regulation No.5, five categories of service were constituted for the Officers and servants of the Board of which, the Tamil Nadu Water Supply and Drainage Board Engineering Subordinate Service, is one. The said service consisted of 14 categories of post of which, Draughtsman Grade III- (Category 5) and Assistant Draughtsman (category 6) are the two. Regulation 50 provided for the respective Appointing Authorities and Regulation No.23 provided that no person shall be eligible for appointment to the category mentioned in column No.(1) of the Table contained thereto by the method specified in column No.(2) of the Table unless he possesses the qualifications specified in the corresponding entries in column (3) thereof. The relevant portion Of the Table for the purposes of our consideration is extracted below: Category Method of appointment “4. Draughtsman, Grade II By Promotion from Draughtsman, Grade III or by direct recruitment by transfer from any other service-including recruitment from among Work Assistants in the Board. Qualifications. ”(1) The Degree in Engineering (Civil or Mechanical) or the L.C.E., L.S.E., D.C.E., L.M.E., or D.M.E., Diploma awarded by the Board of Technical Education and Training, Madras or any Diploma recognised by the said Government of Tamil Nadu as equivalent thereto for appointment under the said Government; and (2) Three years experience as Draughtsman. Explanation I: The Engineering Degree or Diploma qualification not specifically mentioned in these rules possessed by persons already in service as on 22nd July,1971 in respect of categories 1 to 5 shall not adversely affect them and shall not render them liable for being considered for promotion if they satisfy all other conditions. Explanation II. In so far as suitable candidates are available, the persons possessing the certificate qualification in Engineering and who entered service on or before 112. 1972 shall be considered for promotion to all grades of Draughtsmen alongwith the person possessing the degree or diploma in Engineering in the ratio of one certificate holder for every five Degree or Diploma holders. Category Method of appointment 5. 1972 shall be considered for promotion to all grades of Draughtsmen alongwith the person possessing the degree or diploma in Engineering in the ratio of one certificate holder for every five Degree or Diploma holders. Category Method of appointment 5. Draughtsman, Grade III By direct recruitment or promotion from Tracers, or recruitment by transfer from any other service including work charged establishment. Qualifications: Item (1) under Draughtsman, Grade II. Explanation III. The Assistant Draughtsman possessing certificate qualification or any other qualification prescribed for the post of Assistant Draughtsman in the Tamil Nadu Water Supply and Drainage Board Service Regulations, 1972 who entered service as Assistant Draughtsman on or before the 13th December, 1972 and who have put in not less than five years of service from the date of appointment or from the date on which they became fully qualified shall be considered for appointment, as Draughtsman Grade III. A person so appointed shall not be eligible for any further promotion unless he gets himself qualified for such post. Category Method of appointment 6. Asst. Draughtsman . By direct recruitment or recruitment by transfer from any other services including work charged establishment. Qualifications. .(1) Pass in the Government Technical Examination, by the Lower Grade in Geometrical Drawings, Buildings Drawing and Estimating and Freehand outline and Model drawing;or .(2) A completed S.S.L.C., issued under the Authority of the Government of Tamil Nadu with a pass in ‘Engineering’ included as a special subject if the bifurcated courses in Secondary Schools or .(3) A pass in the building and structural Draughtsmanship certificate course of Central Polytechnic, Madras. 4. Prior to the making and coming into force of the Regulations, but immediately after the Board was brought into existence, the required staff were appointed in all categories including for the post of Assistant Draughtsman falling in Category (6) of the Engineering subordinate service. At that point of time the rules governing the appointment to similar categories of post in the Public Health Engineering Department were followed and as per the said rules the certificate holders (Non-Degree and Non-Diploma holders) were also eligible for promotion to the immediate categories of post in the draughtsman category. But, the regulations made in D.P.Ms.No.398, dated 112. At that point of time the rules governing the appointment to similar categories of post in the Public Health Engineering Department were followed and as per the said rules the certificate holders (Non-Degree and Non-Diploma holders) were also eligible for promotion to the immediate categories of post in the draughtsman category. But, the regulations made in D.P.Ms.No.398, dated 112. 1972 did not provide for such an avenue of promotion and only if the person concerned possessed the required qualification for the category of Draughtsman, there was scope for such appointment to category (5) posts. Since, those persons who joined the services of the Board prior to 112. 1972, the date of making of the Regulation by the Board was not aware of this petition and joined the service with such hope and prospects of promotion, the Board, on representations made passed B.P.Ms.No.342, dated 9. 1977, introducing the necessary amendments providing for such promotion and also introducing Explanation III, referred to supra. Immediately before this, the Board by its resolution dated 3. 1977 resolved to make those provisions and had the same duly approved by the Government in G.O.Ms.No.1406, (R.D. & L.A.), dated 20.8.1977 in terms of Sec.73(3) of the Act and also duly notified the same. The sum and substance of the amendments so made is that for appointment by promotion to category (5) viz., Draughtsmen Grade III, the category 6 Assistant Draughtsmen became a feeder category and they should acquire the required Educational qualification, prescribed for Draughtsman Grade III before becoming eligible for such promotion which are the same as those prescribed for Draughtsman Grade II. So far as the Assistant Draughtsmen, who joined service between 14. 1971 and 112. 1972 unaware of such restrictions to be imposed subsequently and under the then prevailing rules under which there was scope for such promotion, Explanation III provided that such of those Assistant Draughtsmen who entered service on or before 112. 1972, on putting in a service of not less than five years of service from the date of appointment shall be considered for promotion to category (5) post but even such person shall not be eligible for any further promotion unless he gets himself qualified for such further posts. The request and representation of the Assistant Draughtsmen, who joined after 112. The request and representation of the Assistant Draughtsmen, who joined after 112. 1972 after coming to know of their conditions of service, as per regulations, for the same treatment, was not acceded to. 5. It is at that stage the above writ petition came to be filed in this Court and before the learned single Judge it appears that the following two grounds were raised: (a) Sec.73 of the Act does not authorise regulations to be made with retrospective effect; and (b)When all Assistant Draughtsmen form a class, based on arbitrary date like 112. 1972, the two classes cannot be carved out therein, when in law they could only form a single unit. The learned single Judge, though held that the treating of those appointed between 14. 1971 and 112. 1972 as belonging to a separate category for differential treatment had not resulted in violation of Arts.14 and 16(1), allowed the writ petition on the first point holding that the impugned regulation made with retrospective effect is without any legality and therefore had to be struck down only relating to its retrospective applicability and further declared that it will be valid prospectively on and from its notification. The appellant Board who was the second respondent before the learned single Judge has filed the above appeal. 6. Mr.V.Sridevan, learned Government Pleader appearing on behalf of the appellant contended that the amendment did not involve any retro-spectivity, that it is merely clarificatory and at any rate it was meant to be effective only prospectively. It was further contended that merely because it governed the fate of a class of persons, who were appointed between 14. 1971 and 112. 1972, the same cannot be held to be retrospective even though the object is to implement the same in respect of promotions to be made after the making of the regulation. It is the stand of the appellant that the reference to retrospectivity has no relevance to the point in issue. Shri G.Venkataraman, while reiterating the stand taken before the learned single Judge invited our attention to ground (b) in paragraph 13 of the affidavit filed in support of the writ petition, which reads thus: “(b) The order dated 9. 1977 seeks to give retrospective effect to the implementation of Explanation III to Regulation by specifying the relevant date as 112. 1972. 1977 seeks to give retrospective effect to the implementation of Explanation III to Regulation by specifying the relevant date as 112. 1972. Any order passed by the respondents can be only prospective and therefore, the Board has no authority or jurisdiction to put back the date to 112. 1972 for its implementation. Therefore, such an, order is illegal and vitiated by errors of juris-diction.” The above ground based upon alleged retrospectivity appears to be wholly miconceived, both factually and in law. The order dated 9. 1977 effects two amendments viz., (i) for the word ‘Tracers’ wherever it occurs, the words ‘Assistant Draughtsmen’ has been substituted, (ii) Explanation III, referred to supra has been added after Explanations I and II after category - Draughtsmen Grade III. Neither in the Preamble nor at any place in the Regulation or the Order there is any factual specification or indication of the amendments having been given any retrospective effect. It appears that after the amendments, the category of persons covered by Ex.III also appears to have been promoted to category (5), Draughtsman, Grade III and there is no material before us to controvert this stand taken in the counter affidavit filed before the learned single Judge. There appears to be some misapprehension about a proper understanding of the grievance made by the first respondent - writ petitioner before the learned single Judge. 7. That apart, it has to be considered as to whether the Ex.III in so far as it lays down for Promotion of an Assistant Draughtsman to the next immediate Post of Draughtsman Grade III specifying the relevant date to be 112. 1972, can be said to be retrospective in operation. The Explanation III added, merely states that the Assistant Draughtsman, who possessed merely the certificate qualification and entered into service as such on or before 112. 1972 (on which date the Original Regulations came into force) and who have put in not less than five years of service shall be considered for promotion and that such persons shall not be entitled to any further promotion unless he gets himself qualified for such post. 1972 (on which date the Original Regulations came into force) and who have put in not less than five years of service shall be considered for promotion and that such persons shall not be entitled to any further promotion unless he gets himself qualified for such post. In the decision reported in J. & K. State v. T.N,.Khosa, A.I.R. 1974 S.C. 1: 1974 Lab.I.C. 1: (1074)1 S.C.C. 19: (1974)1 Lab.L.J. 131: (1974)1 S.C.J. 336, a Constitution Bench of the Apex Court held that it is wrong to characterise the operation of a service rule as retrospective for the reason that it applies to existing employees and that a rule which classifies such employees for promotional purposes operates, undoubtedly, on those who entered service before the framing of the rule but it operates in future in the sense that it governs the future right of promotion of those who are already in service. So far as the impugned regulation is concerned, it operates only in future though it governed the future right of promotion of such of those Assistant Draughtsmen, who entered in the service of the Board on or before 112. 1972. To the same effect is the decision of another decision of the Apex Court, wherein it has been held that when a statutory Rule governing seniority is issued in respect of a service, the said rule would govern all the personnel in service with effect from the date of its promulgation and in so giving effect to the rule in future, there is no element of retroactivity - involved. It has been further held therein that though the rules will not operate to deprive any person of promotions already earned in the post, but for purposes of future promotions and seniority in the Department the principles laid down in the rule will necessarily govern all persons in service-vide J.Kumar v. Union of India, A.I.R. 1982 S.C. 1064: (1982)1 S.C.C. 116 . Consequently, there is no merit in the attack on the ground of alleged retrospectivity of the amendment and we are unable to subscribe our concurrence to the view of the learned single Judge in this regard. Therefore, the ground on which the writ petition was allowed to the extent of retrospectivity no longer survives and the order of the learned single Judge is liable to be set aside. Therefore, the ground on which the writ petition was allowed to the extent of retrospectivity no longer survives and the order of the learned single Judge is liable to be set aside. As a matter of fact, the learned single Judge specifically holds in paragraph 10 of the judgment under appeal before us that the impugned regulation is struck down only relating to its retrospective applicability and in other respects, it will be valid prospective, on and from the date of its notification. 8. The learned counsel for the first respondent at this stage submitted that even though the learned single Judge held against the first respondent herein on the question of violation of Arts.14 and 16(1) of the Constitution of India, he would like to challenge the findings of the learned single Judge, though no appeal as such or any memo in the nature of cross-objections had been filed before this Court against these findings rendered against the first respondent. Since the learned single Judge granted relief to the writ petitioner/first respondent only on the question relating to the retrospectivity and declared that it would be valid prospectively, while holding against the first respondent in respect of the challenge to the validity of the classification, it would have been proper for the first respondent to file a memo of objection or an appeal against such adverse finding. But, be that as it may, the learned counsel/or the first respondent also made his submissions on. the said issue and therefore we have considered that issue also, below. 9. The learned counsel for the first respondent submitted that all the Assistant Draughtsmen, whether joined before or after 112. 1972 belonged to one class and a classification among them based upon a dateline for differential treatment is violative of Arts.14 and 16(1) of the Constitution of India. According to the learned counsel, the classification based on the said dateline has no relevance to the object which according to him is only efficiency of service. The learned counsel while reiterating the submission made before the learned single Judge took us through the findings and conclusions on this aspect in the judgment under appeal. According to the learned counsel, the classification based on the said dateline has no relevance to the object which according to him is only efficiency of service. The learned counsel while reiterating the submission made before the learned single Judge took us through the findings and conclusions on this aspect in the judgment under appeal. It has been often held thai classification is primarily for the legislature or for the statutory Authority charged with the duty of framing the terms and conditions of service and if looked at from the standpoint of the authority making it, the classification is found to rest on reasonable basis, it has to be necessarily upheld. Discrimination in the form of differential treatment is the evidence and is also the inevitable consequence of classification and only if it rests on an unreasonable basis or extraneous considerations it can be said to be invidious and violative of the constitutional guarantee of equality and not otherwise. Classification, thus must be properly speaking really founded on substantial differences which distinguish persons grouped together from those left out of the group and such differential attributes must bear just and rational relation to the object sought to be achieved. Consequently, judicial scrutiny could therefore extend only to the consideration whether the classification rests on a reasonable basis and whether it bears nexus with the object in view. Once it is found to be neither unreal nor unreasonable the Courts are not expected to embark upon a nice or mathematical evaluation of the basis of the classification and substitute their judgment for that of the rule making authority on the need or desirability to classify persons to achieve a particular object. 10. The learned counsel for the first respondent relied upon the decision of the Supreme Court in D.S.Nakara and others v. Union of India, A.I.R. 1983 S.C. 130: 1983 Lab.I.C. 1: (1983)1 S.C.C. 305 : (1983)1 Lab.L.J. 104: (1983)1 S.C.W.R. 390: (1983)1 S.C.J. 188, wherein the classification of pensioners for liberalised payment of pension based solely upon the ground that some retired earlier and some retired later was held to be arbitrary because the differential treatment based upon such a fortuitous circumstances like the date of retirement was considered to be neither an acceptable nor a persuasive reason for the classification. The decision in State of Mysore v. Krish-namurthy, A.I.R. 1973 S.C. 1146: 1973 Lab.I.C. 791, was next referred to wherein the Apex Court rejected a classification for further promotional prospects of members belonging to the erstwhile different units of Accounts service relating to P.W.D. and the Local Fund Audit, even after their complete integration into one single unit of service based upon the earlier differences which did not exist after their integration. In that context the Apex court upheld the view taken by the Mysore High Court that neither a fortuitous artificial division in the post nor the unconstitutional practice of making an unjustifiable discrimination in promotional chances of Government servants belonging to what was really a single category without any reference either to merit or seniority or educational qualifications could justify the differences in promotional chances. In our view there can be no analogy of those cases to the case on hand and the ratio of the decision in those cases do not help the first respondent to substantiate his stand on the peculiar facts and circumstances of the present case. 11. So far as the case on hand is concerned, it could be seen that the qualification prescribed for the post of Draughtsmen Grade III in the service of Board, as per the Regulation in question is a Degree in Engineering (Civil or Mechanical) or the L.C.E., or L.S.E., or D.C.E., Diploma awarded by the Board of Technical Education and Training, Madras. The method of recruitment for the said post is by promotion from the post of Tracer, since substituted as, Assistant Draughtsman or recruitment by transfer, from any other service including workcharge Establishment There are also Assistant Draughtsman, possessing the following qualifications: .(a) Certificate course in Engineering; .(b) Certificate course of Draughtsman, in Civil Engineering of I.I.T.; .(c) S.S.L.C., (Bifurcated course) and .(d) Diploma in Mechanical Engineering. And such Assistant Draughtsman, could not be appointed as Draughtsmen. Since the Authorities of the Board considered the fact that for the promotion of the Assistant Draughtsmen, to the Post of Draughtsman Grade III in the Regulations originally made there was no provision and having regard to the fact that those Assistant Draughtsmen who entered service prior to 112. And such Assistant Draughtsman, could not be appointed as Draughtsmen. Since the Authorities of the Board considered the fact that for the promotion of the Assistant Draughtsmen, to the Post of Draughtsman Grade III in the Regulations originally made there was no provision and having regard to the fact that those Assistant Draughtsmen who entered service prior to 112. 1972 should be given a chance for promotion as at the time of their entry into the service they were not aware of the fact that they would be rendered ineligible for promotion in the Regulations to come thereafter the Board considered the necessity to safeguard the interests of such persons. The distinct categorisation and classification of such of those Assistant Draughtsmen who entered into service prior to 112. 1972 with required qualification for the said post but who did not possess Degree or Diploma stipulated for the post of Draughtsman Grade III appears to be reasonable, just and relevant for more than one reason viz., (i) That when they entered in the Board Service prior to 112. 1972, there was no regulation as such and they were totally unaware of the regulation to come and the stipulations to be made therein in contrast to those who entered service after the Regulations were made and knowing fully well their rights and obligations and conditions of service, under the Regulations, (ii) All those appointed between 14. 1971 and 112. 1972 are treated alike and they are constituted as a distinct class or group, with no further difference, among them, (iii) They are also seniors to those who entered service after 112. 1972 and consequently, there could be no room for any legal grievance whatsoever, and (iv) The Special Circumstances like the one that they will be a diminishing category. Having regard to these peculiar features, we consider that the classification is founded as an intelligible differentia which distinguishes those appointed prior to 112. 1972 who are grouped together for the purposes of the benefit of Ex.III in question from the others who are appointed after 112. 1972 who were left of the said group and that the same has reasonable and rational relation to the object sought to be achieved. 12. 1972 who are grouped together for the purposes of the benefit of Ex.III in question from the others who are appointed after 112. 1972 who were left of the said group and that the same has reasonable and rational relation to the object sought to be achieved. 12. In the decision reported in Life Insurance Corporation of India and another v. Srivastava and others, (1987)2 L.L.J. 414, the Apex court upheld the classification of employees in different categories of service for the purpose of fixing age for superannuation depending upon the date of entry into service holding that such a factor is not something which is unusual when such, classification is found necessary on account of historical facts and the need for treating the employees in a fair and just way. Similarly, in the decision reported in B.S.Yadav v. Central Bank of India, A.I.R. 1987 S.C. 1706: (1987)3 S.C.C. 120 , once again the Apex Court had to consider the validity or otherwise of fixing differential ages of superannuation to Bank Officers by classifying those inducted prior to Nationalisation as a distinct group from those who were inducted into service after such date of nationalisation. The Supreme Court while upholding such a classification was of the view that the question involved in such situations is not one of mere competence and that it involves justice and fairness too. The reason for the distinction between the two groups based upon the criteria of joining service before the date of nationalisation and those inducted into service after the date of nationalisation was held to be a good reason and found further to be necessary too in order to secure the services of the former group of employees without causing much dissatisfaction to them. We consider that the said ratio squarely apply to the peculiar facts and circumstances of the case under our consideration and we cannot therefore consider the move of the Board in showing a limited concession to those employed before 112. 1972 to be unreasonable or invidious vis-a-vis those who joined the services of the Board fully aware of their rights after the making of the Regulation which inevitably constituted their condition of service, so as to warrant our interference. 1972 to be unreasonable or invidious vis-a-vis those who joined the services of the Board fully aware of their rights after the making of the Regulation which inevitably constituted their condition of service, so as to warrant our interference. We are in entire agreement with the conclusions and findings of the learned single Judge on this aspect of the matter and we have not been persuaded for any effective or justifying reason to take a different view than the one arrived at by the learned single Judge. 13. The learned counsel for the first respondent further sought to argue that the Assistant Draughtsman appointed after 112. 1972 also should be promoted as Draughtsman Grade III and that there should be suitable revision of the qualification since according to the learned counsel in similar Governmental undertakings such promotions are given. First of all, we find that no such plea has been raised before the learned single Judge at the hearing of writ petition and we cannot countenance such a plea at this stage before us, and that too in an appeal filed by another party. Secondly, it is not for this Court to suggest or dictate as to what should be qualifications to be prescribed or stipulated for appointment or promotion to a post in a particular service of a particular undertaking and such matters have been always held to be within the competency of the competent Authority (in this case the Board which has to make regulations subject to the approval of the Government) and this power, subject to the safeguards secured under Arts.14 and 16 of the Constitution of India is within the exclusive discretion of the Rule making Body. For all the reasons stated above, we set aside the reasoning of the learned single Judge which made the learned single Judge to allow the writ petition and allow the appeal and consequently direct that the writ petition filed by the first respondent be dismissed. But, in the circumstances of the case, there will be no order as to costs.