Section 52(b) in The Limestone And Dolomite Mines Labour Welfare Fund Rules, 1973
(b)notwithstanding any such concealment of particulars as is mentioned in clause (a), the Commissioner has in consequence of information in his possession, reason to believe that any limestone or dolomite on which duty of excise is payable has escaped levy of the duty of excise, the Commissioner may, in cases falling under clause (a), at any time within four years, and in cases falling under clause (b), at any time within two years of the end of the month during which the duty of excise should have been paid, assess the duty of excise payable thereon and all the provisions of these rules shall apply to the duty of excise so assessed as if assessment were included in the final assessment order as provided under rule 49 or rule 50 as the case may be:
