(b)the total income declared in the return of income filed under section 263 of this Act or section 139 of Income-tax Act, 1961, or in response to a notice under section 268(1) of this Act or section 142(1) of Income-tax Act, 1961 prior to the date of initiation of the search or the date of requisition, in respect of any of the tax year falling within the block period, and not covered under clause (a);