6. (1) The Government may by notification in the official Gazette make rules relating to any class of savings certificate. (2) In particular and without prejudice to the generality of the foregoing power, such rules may provide for the application for, the issue, maximum limits of holding and discharge of, and conditions as to interest or discount relating to, any class of savings certificate, and may also provide-(a) that where any such maximum limits of holdings are exceeded, no interest shall be payable on the amount of such excess;(b) that if any interest has been paid on any amount of such excess, it shall be recoverable as an arrear of land-revenue or in such other manner as the rules may prescribe. (3) All rules relating to-(a) the Post Office Twelve-Year National Savings Certificates in force at the commencement of this Ordinance,(b) any other class of savings certificate in force at the time when a direction in pursuance of clause (b) of sub-section (2) of section 1 is made in respect thereof-shall, so far as they are not inconsistent with the provisions of this Ordinance, continue in force until they are duly rescinded or amended, and shall be deemed to have been made under this Ordinance.