Section 413A(2) in The Calcutta Municipal Corporation Act, 1980
(2)Where the construction of the building has been completed by such person on or before the commencement of the Calcutta Municipal Corporation (Amendment) Act, 1996, and the document of title to land has been granted by the State Government, such person shall apply for regularization in accordance with the provisions of sub-section (1) within [three years] [Words substituted by W.B. Act 26 of 1997.] from the date of commencement of the Calcutta Municipal Corporation (Amendment) Act, 1996.