Section 9(3) in The Mines And Minerals (Development And Regulation) Act, 1957
(3)The Central Government may, by notification in the Official Gazette, amend the Second Schedule so as to enhance or reduce the rate at which royalty shall be payable in respect of any mineral with effect from such date as may be specified in the notification:[Provided that the Central Government shall not enhance the rate of royalty in respect of any mineral more than once during any period of ] [ Substituted by Act 56 of 1972, Section 4, for the proviso (w.e.f. 12.9.1972).][three years] [ Substituted by Act 37 of 1986, Section 8, for " four years" (w.e.f. 10.2.1987).].]
