Section 21(1)(v) in The Punjab Minor Mineral Concession Rules, 1964
(v)Unless the Government, for sufficient reasons permits otherwise, the lessee shall commence mining operations within six months from the date of [execution] [Substituted for 'execution' by GSR 239 dated 27.9.1965.] of the lease and shall thereafter conduct such operations in a proper, skillful and workman-like manner.