Amendment to Section 20 extends applicability to supplies taxable under section 9 or section 5(3)/(4) of IGST. The amendment to section 20 inserts the phrase 'of this Act or under sub section (3) or sub section (4) of section 5 of the Integrated Goods and Services Tax Act, 2017' after 'section 9' in sub sections (1) and (2), thereby extending section 20's applicability to supplies taxable under the specified sub sections of the IGST Act, effective 1 April 2025.