[Commutation of annuity.
90. Any payment in commutation of annuity shall not exceed—
(a) | in a case where the employee receives any gratuity, the commuted value of [one-third] of the annuity which he is normally entitled to receive, and | |
(b) | in any other case, the commuted value of [one-half] of such annuity, |
such commuted value being determined having regard to the age of the recipient, the state of his health, the rate of interest and officially recognised tables of mortality.]