Income-tax Act, 1961
Notwithstanding anything contained in this Chapter, no loss which has not been determined in pursuance of a return filed [in accordance with the provisions of sub-section (3) of section 139], shall be carried forward and set off under sub-section (1) of section 72 or sub-section (2) of section 73 [or sub-section (2) of section 73A] or [sub-section (1) or sub-section (3) of section 74] [or sub-section (3) of section 74A]. [