In section 12A of the Income-tax Act, in clause (b), for the words and figures "the provisions of section 11 and section 12 exceeds fifty-thousand rupees in any previous year", the words and figures "the provisions of section 11 and section 12 exceeds the maximum amount which is not chargeable to income-tax in any previous year" shall be substituted with effect from the 1st day of April, 2006.