Ali, J.- In this application under Article 226 of the Consti­tution of India, the petitioner challenges the provision of age limit contained under proviso (b) to Clause (c) of Sub-rule (1) of Rule 6 of the Assam Taxation Services Rules, 1962 as viol­ative of the provisions of Articles 14 and 16 of the Constitution. The circumstances leading to the present writ petition are as follows. The petitioner Shri Tarinidhar Choudhury was appointed as a Lower Division Assistant in the Office of the Superin­tendent of Taxes, Gauhati in the Assam Taxation Services in 1948, He joined the post on 1.6.48, subsequently he was promoted as an Upper Division Assistant and on 1.10.75 he was promoted to the post of Head Assistant in the unit office of Gauhati. The conditions of service of the employees of Assam Taxation Services are regulated by the provisions of the Assam Taxation Services Rules, 1962 as amended up-to-date (Hencefor­th to be called as the Rules.) Under Rule 3 of the Rules, there a are three classes of services appertaining to Assam Taxation Services, viz., Class-I-Asstt. Commissioner of Taxes, Class-II-Superintendent of Taxes or Agricultural Income-Tax Officers and Class-III-Inspectors of Taxes. Each of these classes constitute a separate cadre. 2. According to Rule 7(1) of the Rules, the Govt. has to prepare a list of officers eligible for promotion (to be called as gradation list) in order of seniority-cum-merit of each cadre and accordingly the Assam Govt. prepared and finalised a grada­tion list of ministerial officers of Assam Taxation Services in-1977 which is still in force. In the aforesaid gradation list, the name of the petitioner stands at SI. No. 2 and names of respondents No. 5 to 17 stand in SI. No. 118, 119, 120, 122, 124, 125, 126, 127, 130, 131, 132, 133 and 135 respectively. Under the provi­sions of Rule 6(1)(c) of the Rules, 25% of the vacancies in Class-III cadre (Inspectors of Taxes) have to be filled up at a time by promotion from the ministerial Govt. servants of the Assam Taxation Services and as such the petitioner's claim to promo­tion fall due immediately after SI. No. 1 of the gradation list. 3. Under the provi­sions of Rule 6(1)(c) of the Rules, 25% of the vacancies in Class-III cadre (Inspectors of Taxes) have to be filled up at a time by promotion from the ministerial Govt. servants of the Assam Taxation Services and as such the petitioner's claim to promo­tion fall due immediately after SI. No. 1 of the gradation list. 3. But no consideration of the claim of the petitioner was made and respondents No. 5 to 17 as well as 1, Shri S.K. Rabha (Since deceased) though occupying positions in the gradation list much junior to the position of the petitioner were promoted in March, 1979 as Inspectors of Taxes vide order of the Assam Government No. FEB. 117/77/Pt./75 dated 15.3.79 in exercise of the powers under Rule 6(1)(c) of the Rules. Rule 6 of the Rules which regulates the promotion of employees in the Assam Taxation Service is as follows :- "6. Promotion-(1) Promotion shall be subject to the follo­wing reservations :- (a) All vacancies to the Class-I cadre shall be filled by promotion of officers belonging to the Class-II cadre. (b) Fifty per cent of vacancies to be filled at a time in the Class-II cadre shall be by promotion of mem­bers belonging to the Class-III cadre. (c) Twenty-five per cent of vacancies to be filled at a time in the Class-III cadre shall be by promotion of ministerial Government servants : Provided that a ministerial Govt. servant shall for promotion satisfy the following conditions :- (a) That he has rendered atleast 10 years (subsequ­ently 8 years) of service in the office of the Comm­issioner or any subordinate office, and (b) That he does not cross the age of 42 years on the first day of January of the year in which his promotion is considered by the Commissioner." 4. The petitioner having not been promoted though occu­pying a senior position in the gradation list, represented to the Government against the supersession and was informed that under proviso (b) to clause (c) of sub-rule (1) of Rule 6, he was dis­qualified due to his having crossed the age of 42 years and that for this he was not promoted. The petitioner having not been promoted though occu­pying a senior position in the gradation list, represented to the Government against the supersession and was informed that under proviso (b) to clause (c) of sub-rule (1) of Rule 6, he was dis­qualified due to his having crossed the age of 42 years and that for this he was not promoted. The petitioner, therefore, challenges the impugned rule on the grounds, firstly that by imposing the age limit of 42 years, the Rule has put obstruction to a number of ministerial staff holding the same post and keeping the avenue of promotion with respect to others of the same post free from any obstacle, secondly that this obstacle has been put only with regard to the promotional posts of cadre III, whereas no such hindrance is there with regard to the other two promo­tional cadres, thirdly that this bar of age limit denies the funda­mental rights of some of the employees as guaranteed under Article 14 and Article 16 of the Constitution, fourthly that this discrimination is not based on any reasonable ground, fifthly that this distinction between a group of employees of the same post viz-a-viz the other employees of the same posts has no nexus with the object of such distinction, sixthly that this distinction gives a premium on inexperience and inefficiency and seventhly that the impugned provision of the rule is ultra vires the pro­visions of Articles 14 and 16 of the Constitution. As such the petitioner prays for striking down the impugned rule. 5. In the affidavit-in-opposition on behalf of the respon­dents No. 1 and 2, it is stated that the posts of Lower Division Assistant, Upper Division Assistant and Head Assistant in the Office of the Superintendent of Taxes are not included in the Assam Taxation Services, where for the Rules are not applicable SB the case of the petitioner, that the gradation list alluded to by the petitioner is a list of all ministerial staff prepared in order of seniority including all establishments under the Commissioner of Taxes, Assam. It was not a list for the purpose of promotion to different cadres of the Assam Taxation Service as contemplated under Rule 7(1) of the Rules and that the case of the petitioner was considered earlier to his attainment of 42 years of age but could not be promoted as his service re­cord was not favourable. It was not a list for the purpose of promotion to different cadres of the Assam Taxation Service as contemplated under Rule 7(1) of the Rules and that the case of the petitioner was considered earlier to his attainment of 42 years of age but could not be promoted as his service re­cord was not favourable. It is further alleged that at the second time when the case of the petitioner was taken up for consideration, it was found that he had already crossed 42 years and as such he was not found eligible for promotion. It is further contended that the petitioner was elevated to the post Head Assistant but had to be reverted. It is also stated that formerly a period of 10 years service in the taxation department was a pre-condition form eligibility to be promoted under rule 6 of the Rules and maximum age limit of 40 years was prescri­bed for the same purpose. But, subsequently the restriction was relaxed and the period of service in the taxation department was reduced to 8 years and the upper age limit was raised to 42 years with effect from 1.1.78. In justifying the aforesaid res­triction in the matter of promotion, the affidavit-in opposition says "It may be mentioned that the nature of duties of the ministerial staff of the taxation department is different from that of the members of the Assam Taxation Services. While the ministerial staff has to do purely clerical work, the members of the Assam Taxation Services are entrusted with administra­tive responsibilities which involve outdoor work and exercise of discretionary powers under different taxation measures adminis­tered by the department. It is, therefore, after an objective assessment of the nature of duties and functions of these two classes of Govt. servants, that Government decided that after a number of years of service in ministerial post and attainment of a particular age, a member of the ministerial staff may not be suitable for recruitment to the Assam Taxation Service, duties and functions of which are entirely different as stated earlier. The absence of a age bar for promotion within the service itself is justified by the fact that the members of the Service in diffe­rent classes have to discharge duties and perform functions which by and large are similar in nature if not identical. 6. The absence of a age bar for promotion within the service itself is justified by the fact that the members of the Service in diffe­rent classes have to discharge duties and perform functions which by and large are similar in nature if not identical. 6. The case put in a simplified way is that in the Assam Taxation Service, there are three classes, viz., the Assam Taxa­tion Service class I. The members of this class are called Asstt. Commissioners of Taxes and constitute a cadre belonging to Class I Government service. The second class is Assam Taxation Services Class II. The members of this class are called Superin­tendents of Taxes or Agricultural Income-tax Officers as the case may be and constitute a separate cadre belonging to Class II Government service. The third class is the Assam Taxation Service Class III. The members of this class are called Inspectors of Taxes and constitute a separate cadre belonging to Class III Government Servants. Rule 5 of the Rules contains the method of recruitment. Recruitment to the service shall be made (a) by promotion in accordance with rule 7 and/or (b) through competitive examination in accordance with rule 8. Rule 6 of the Rules provides for promotion as follows : (1) Promotion shall be subject to the following reser­vations :- (a) All vacancies to the Class I cadre shall be filled by promotion of officers belonging to the Class-II cadre, (b) Fifty per cent of the vacancies to be filled at a time in the Clase II cadre shall be by promo­tion of members belonging to Class III cadre, (c) Twenty-five per cent of vacancies to be filled at a time in the Class-Ill cadre shall be by promo­tion with ministerial Government servants, provided : (a) That he has rendered atleast 8 years of service in the office of the Commissioner or any sub­ordinate office, and (b) That he does not cross the age of 42 years on the first day of January of the year in which his promotion is considered by the Co­mmission. Rule 7 provides for selection for promotion as follows :- (1) Government shall prepare a list of officers eligible for promotion in any case not exceeding four times the number of vacancies in the order of seniority-cum merit and shall forward it to the Commission together with such other documents as may be rele­vant for the purpose of making a selection by the Commission. (2) The Commission shall consider the list along with other documents received from Government and forward to Government after such examination as may be deemed necessary a list of names in the order of preference. Remaining portion of the Rule being not relevent for our purpose is not reproduced here. 7. It is further found that in the case of the 25% of the vacancies to be filled at a time in the Class III cadre, it shall be by promotion of ministerial Government servants who fulfill the following two conditions one being that a ministerial Govern­ment servant must have rendered atleast 8 years' of service in the office of the Commissioner or any subordinate office and the other being that he must not have crossed 42 years of age of the first day of January of the year in which his promotion is considered by the Commission. It is therefore found that while the condition of 8 years service in the office of the Commissioner or any subordinate office is applicable to all the employees of that class, the other condition viz, the age limit of 42 years is a differentia creating two sub-classes of the same class of employees with the consequence that those who have not crossed the age of 42 years will be eligible for promotion and those who have crossed the age limit of 42 years will be debarred from promotion. The petitioner's case is that this amounts to discri­mination not maintainable under the provisions of Articles 14 or 16 of the Constitution. The petitioner's case is that this amounts to discri­mination not maintainable under the provisions of Articles 14 or 16 of the Constitution. Article 14 of the Constitution reads as follows : "The State shall not deny to any person equality before the law or the equal protection of the laws within the territory of India." Article 16(1) of the Constitution reads as follows: "There shall be equality of opportunity for all citizens in matters relating to employment or appointment to any office under the State." In the State of Mysore vs. P. Narasinga Rao, AIR 1968 349, it was held that Article 14 docs not forbid reasonable classification for the purposes of legislation and that when any impugned rule or statutory provision is assailed on the ground that it contravenes Article 14, its validity can be sustained if two tests are satisfied, the first test being the classification on which It is founded must be based on a knowledgeable differentia which distinguishes persons or things grouped together from others left out of the group and the second test being that the differentia in question must have a reasonable relation to the object sought to be achieved by the rule or statutory provision in question it was further held in that case that Article 16 is only au instance of the application of the general rule of equality laid down under Article 14 and that it should be construed as such. Accordingly to the ratio of that case, that is no denial of equality of opportunity unless the person who complains of discrimination is equally situated with person or persons who are alleged to have been favoured. Further it was held that Article 16(1) does not bar a reasonable classification of employees or reasonable tests for their selection and that provisions of Article 14 or Article 16 do not exclude the laying down of selective tests nor do they preclude the Government from laying down quali­fications for the post in question including general classifications relating to the suitability of the candidate for public service as such. In this connection learned Counsel for the petitioner re­ferred to S.M. Pandit v. State of Gujrat, AIR 1972 SC 252 . The facts of that case were that till the year 1950 the posts of Deputy Collectors were filled by Bombay Government partly by direct recruitment and partly by promotion from the cadre of Mamlatdars. In this connection learned Counsel for the petitioner re­ferred to S.M. Pandit v. State of Gujrat, AIR 1972 SC 252 . The facts of that case were that till the year 1950 the posts of Deputy Collectors were filled by Bombay Government partly by direct recruitment and partly by promotion from the cadre of Mamlatdars. On February 6th, 1950, the Government decided to fill up those posts only by promotion from the cadre of Mamlatdars. At the same time it decided to introduce the system of direct recruitment to the post of Mamlatdars who in the first instance wore put on probation for two years and if found suitable would be confirmed. It was further decided that 50% of the post of Dy. Collectors will be reserved for promotion of direct recruits in the cadre of Mamlatdars and the other 50% for the promotee Mamlatdars. In 1959 Bombay Govern­ment introduced the change in the mode of recruitment to the posts of Deputy Collectors. In pursuance of the resolution of Go­vernment of Bombay, the Bombay Civil Service Classification and Recruitment Rules were changed and the amended Rules read as follows : "(1) Appointment to the posts of Deputy Collectors shall be made either by nomination or by promotion of suitable Mamlatdars. Provided that the ratio of appo­intment by nomination and by promotion shall as far as possible be 50 : 50. Provided further that half the vacan­cies reserved for appointment by promotion shall be filled by directly recruited Mamlatdars who have put in at least 7 year's service in the post including the period spent on probation, etc. etc." After the formation of the State of Gujrat, the Govt. of Gujrat slightly altered the recruitment rules relating to the posts of Deputy Collectors. Rule 3 of these rules is as follows : “(3) The ratio of appointment in the available vaca­ncies by direct selection and promotion would be 50 : 50. But half the vacancies reserved for appointment by promotion shall be filled by directly recruited Mamlatdars who have put in at-least 7 year's service including the period spent on probation." Rule 3 of the rules is similar to the second proviso to Rule f in the Bombay Civil Services Classification and Recruitment Rules framed in 1959. But half the vacancies reserved for appointment by promotion shall be filled by directly recruited Mamlatdars who have put in at-least 7 year's service including the period spent on probation." Rule 3 of the rules is similar to the second proviso to Rule f in the Bombay Civil Services Classification and Recruitment Rules framed in 1959. The question is whether the second pro­viso to Rule I of the Bombay Civil Services Classification and Recruitment Rules and Rule 3 of the Rules framed by the Gujrat Government are violative of Articles 14 and 16 of the Constitu­tion. The High Court concluded that the impugned Rules violate Articles 14 and 16. It held the opinion that both the directly rec­ruited Mamlatdars as well as the promotee Mamlatdars formed one class and that it was not competent for the Government to discriminate between the directly recruited Mamlatdars and the promotee Mamlatdars in the matter of their further promo­tion. Before the Supreme Court it was argued by the learned Counsel for the appellants that directly recruited Mamlatdars and the promotee Mamlatdars formed two different classes. The Supreme Court upholding the view of the High Court found that both the directly recruited Mamlatdars as well as the promotee Mamlat­dars were designated as Mamlatdars having the same pay scale and that they had to discharge the same functions. The Supreme Court rejected the view that because the directly recruited Mamlatdars had to put in a certain minimum period of service before their promotion to the posts of Deputy Collectors, it did not mean that the two groups were kept apart. The Supreme Court therefore upheld the conclusion of the High Court. In N. S. Subba Rao vs. State of Mysore and another reported in Labour Law Journal Vol II 1974 P. 19, the case of the petitioner was that the Mysore General Services Revenue Subordinate Branch Recruitment Rules, 1961 were framed whereby provision was made for the recruitment of village Accountant. Qualification fixed for the direct recruitment was a pass in S. S. L C. Exam. The said qualification was relaxed in respect of persons who had already served as Village Accountants under the M. V. O. Act, 1908. For them it was sufficient if they have had passed VIII standard and were within 50 years of age. Qualification fixed for the direct recruitment was a pass in S. S. L C. Exam. The said qualification was relaxed in respect of persons who had already served as Village Accountants under the M. V. O. Act, 1908. For them it was sufficient if they have had passed VIII standard and were within 50 years of age. The petitioner who had passed only VII standard was selected as Village Accountant along with other 141 candidates, some of whom had passed S. S. L. C. Examination. All of them were appointed as Village Accountants in the pay scale of Rs 65/- Rs. 90/-. All of them belonged to one cadre with one pay scale of Rs. 65-90. The pay scale was revised later on. By the new rules a discrimination was brought about in the pay scales on the basis of the qua­lifications possessed by the Village Accountants. The Village Accountants who had passed S.S.L.C. Exam, were given the pay scale of Rs. 90/- Rs. 200/- and for the non-S.S.L.C. Village Acco­untants a lesser pay scale of Rs. 80/- Rs 145/- was prescribed. The petitioner was given the lesser pay scale. It was found in that case that all the Village Accountants irrespective of their qualifications formed, one class or cadre, that everybody posse­ssed the minimum qualification prescribed for the post, that they were recruited by one method, that there was a common training for them and that they had no separate avenues of promotion and that this being the position, the State could not make any discrimination in the matters of employment as be­tween members of the same class. It was therefore concluded that by not granting the higher revised pay scale to the peti­tioner, the equality Clause guaranteed under Articles 14 and 16 (1) was offended. 8. In the instant case all the ministerial Government ser­vants referred to in Clause (c) of Sub-rule (1) of Rule 6 form one class or cadre. Every one of them possesses the minimum qualification prescribed for the post and they have no separate avenues of promotion. They have also the same pay scale and they discharge the same functions. Under these circumstances grouping (hem into two separate classes on the basis of the age limit of 42 years for the purpose of promotion is against the equality clause as guaranteed under Articles 14 and 16 (1) of the Constitution. They have also the same pay scale and they discharge the same functions. Under these circumstances grouping (hem into two separate classes on the basis of the age limit of 42 years for the purpose of promotion is against the equality clause as guaranteed under Articles 14 and 16 (1) of the Constitution. The differentia does not have any reas­onable nexus with the object of such discrimination. The object as gathered from the affidavit-in-opposition is that the promo­tional post implies out-door work and exercise of discretionary powers under different taxation measures administered by the Department. It is further clarified in the affidavit-in-opposition the respondents that after a number of years of service in the ministerial post and attainment of a particular age, a members of the ministerial staff may not be suitable for recruitment to the Assam Taxation Services, duties and functions of which are entirely different. But it is common knowledge that suitability for out-door work of an employee may not be conditional to a particular age limit. In the present case by the age limit of 42 years a differentiation has been created between those who are upto the age of 42 years and those who are beyond the age of 42 years. In the circumstances of the case a person beyond the age of 42 years becomes inefficient for out-door duties and for discharging the responsibilities attached to the promotional post. But as soon as he gets promotion to; the post of Inspector of Taxes, an employee not beyond the age of 42 years does not become inefficient in those respects even if he crosses 42 years and continues to remain efficient in all respects with the progress of age beyond 42 years. But the same employee before getting promotion is taken to be inefficient in those respects as soon as he crosses the age of 42 years. This is an anomalous position beyond reconciliation. So there is no reasonable or rational nexus between the differentia and the object of the differentia. It is an arbitrary basis by which an artificial division has been created between employees of the same class. This being so, the impugned Rule is violative of Articles 14 and 16(1) of the Constitution of India. 9. In the result the petition is allowed. It is an arbitrary basis by which an artificial division has been created between employees of the same class. This being so, the impugned Rule is violative of Articles 14 and 16(1) of the Constitution of India. 9. In the result the petition is allowed. The impugned proviso (b) to Clause (c) of Sub-rule (1) of Rule 6 is struck down as ultra vires the Constitution of India. Parties will bear their own costs.