Section 1A(46)(d) in The Merchant Shipping (Prevention of Pollution by Oil from Ships) Rules, 2010
(d)which has undergone a major conversion -(i)for which the contract is placed on or before the 31st December, 1975; or(ii)in the absence of a contract, the construction work of which is begun on or before the 30th June, 1976; or(iii)'which is completed on or before the 31st December, 1979.