When calculating the age of an official of a constitutional body, the age shall be calculated on the basis of the age from which he first retires:-
(a) Age to be obtained from the date or year of birth mentioned in the certificate of the educational institution submitted by him,
(b) the age to be obtained from the day or year of birth entered in his certificate of citizenship, or
(c) Age to be obtained from the date or year of birth written in his personal job description (citrol).