regards this point can be summarised to the effect that, where a promotion is to be given on the principle of “seniority-cum-merit”, such promotion will not automatically be granted on the basis of seniority alone. Efficiency of administration cannot be compromised with at any cost. Thus, in order to meet said requirements, all eligible candidates in the feeder cadre must be subject to a process of assessment to determine whether or not an individual in fact possesses the specified minimum necessary merit, and in the event that he does possess the same, his case must be considered giving due weightage to his seniority. Furthermore, the statutory authority must adopt a bona fide and reasonable method to determine the minimum necessary merit, as is required to be possessed by the eligible candidate. It must also take into account his period of service, educational qualifications, his performance during his past service for a particular period, his written test, interview, etc. The authority must further be competent to allocate separate maximum marks on each of the aforesaid counts. Fixing such criteria, or providing for minimum necessary merit, falls within the exclusive domain of policy-making. Thus, it cannot be interfered with by courts in the exercise of their judicial powers, unless the same is found to be off the mark, unreasonable, or mala fide."