Section 202(7) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(7)Commander and above. - (a) Acting ranks of Commander and above shall only be granted to officers who are selected to fill appointments carrying a rank higher than their confirmed rank, and will become effective from the date an officer actually assumes and performs duty in that appointment. The grant of acting rank shall, however, not be automatic upon an officer assuming the higher appointment.(b)Selection of officers for the grant of acting rank shall be primarily based on merit, but other. factors such as availability and/or suitability of an officer to fill a particular appointment shall also be taken into consideration.
