Section 268(3)(a) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(a)Except as provided in Regulation 270, Continuous Service men who, after completing the period of their initial Continuous Service enrolment, volunteer and are permitted to continue to serve, shall, subject to the provisions of Regulation 269(2), be re-enrolled by the Captain Naval Barracks, for a period not exceeding that required to complete the service necessary to qualify for the minimum pension. In exceptional cases, however, where the exigencies of the Service so warrant, the prior sanction of the Chief of the Naval Staff may be obtained instead for the re-enrolment of the sailor for a period not exceeding 8 years.(aa)[ Re-enrolment of sailors who have been [promoted] [Inserted by S.R.O. 309, dated 17th October, 1969] to the [rank] [Substitued by S.R.O. 192, dated 10th September, 1973] of Master Chief Petty Officers Class I and Class II shall be permissible upto 30 years of service in spells not exceeding five years at a time with the previous approval of the Chief of the Naval Staff. The total period of engagement shall not normally exceed 30 years. The Chief of the Naval Staff may at his discretion, grant extentions of engagement beyond 30 years upto a maximum of five years at a time until the prescribed age of compulsory retirement.]