JUDGMENT Barin Ghosh, C.J. (Oral) In this writ petition, the Rules of promotion are under challenge, inasmuch as promotion to the petitioner has been denied. The Rules have been challenged on the ground that consideration of the entire service record with special emphasis for the last 10 years is not appropriate. Secondly, it has been contended that the Rules under which promotions were considered did not apply to the vacancies in the promotional posts, as those vacancies were available since prior to the date of coming into force of the Rules which were applied. 2. The ground of challenge is, therefore, on rationality of the Rules. The Rules, as framed, cannot be said to be irrational. The Rules provide consideration of the entire service records and accordingly insist that there must be subjective satisfaction that the person concerned, whose case of promotion is being considered, had been a useful employee of the Government from the date he joined the services of the Government. While emphasis has been given to last few years immediately before promotion, that signifies that there must be subjective satisfaction that the person concerned had been such an employee that apart from being useful to the work for the purpose for which he had been appointed, he has achieved such distinction that a promotion in his favour would enhance the functioning of the Government. There is, therefore, on that ground, no scope of interference with the subject Rules. 3. When promotion is to be accorded, the same is to be accorded on the basis of law then applicable, inasmuch as when a law exists that law removes all previous laws dealing with the subject, unless expressly preserved. The vacancy whether accrued before or after coming into force of the existing law is of no consequence. When steps would be taken to fill them up, law then applicable can only be applied for at that time the previous law is not in existence. 4. In the event, however, by reason of a previous law substantial rights have been created in favour of someone and the same is exhaustible in terms of the law prevalent, by postponing exhaustion thereof within the law then applicable, if by changing the law interference is caused to such vested exhaustible rights, the Courts are competent to protect and preserve the same. In the case at hand, such a case has not been made out. 5. There is, therefore, nothing further to be done in the writ petition. The same is dismissed. 6. In course of submission, learned counsel for the petitioner submitted that even under the existing law, the petitioner had right to know final gradation given to him in his Annual Confidential Reports and if he has lost for non-supply of information's pertaining thereto, his client has a right to make an appropriate representation in that regard. Since that is not the subject matter of the present writ petition, we have not gone into that aspect and accordingly keep the same open.