Section 7: The debentures shall be redeemable either-

(a) at par on a fixed date to be declared on the issue of the debentures such date not being later than sixty years from the date of issue: Provided that the Governor, or the Crown Agents acting on his behalf, may reserve the option to redeem the debentures prior to such date on such conditions as may be declared at the time of issue; or (b) by annual drawings at par or at the option of the Governor, or the Crown Agents acting on his behalf, by purchase at or below par.