Section 16(1) of the Central Act enacts: "16(1)(a) All mining leases granted before the commencement of the Mines and Minerals (Regulation and Development) Amendment Act, 1972, if in force at such commencement, shall be brought into conformity with the provisions of this Act, and the rules made thereunder, within six months from such commencement, or such further time as the Central Government may, by general or special order, specify in this behalf (b) Where the rights under any mining lease, granted by the proprietor of an estate or tenure before the commencement of the Mines and Minerals (Regulation and Development) Amendment Act, 1972, have vested, on or 695 after the 25th day of October, 1949, in the State Government in pursuance of the provisions of any Act of any Provincial or State Legislature which provides for the acquisition of estates or tenures or provides for agrarian reform, such mining lease shall be brought into conformity with the provisions of this Act and the rules made thereunder within six months from the commencement of the Mines and Minerals (Regulation and Development) Amendment Act, 1972, or within such further time as the Central Government may, by general or special order, specify in this behalf".