Input tax credit apportionment: credit limited where supplies serve non business or exempt purposes, with specified blocked credits. This section restricts input tax credit to the portion attributable to business or taxable supplies, prescribes that exempt supplies (including reverse charge transactions, securities, sale of land and certain building sales) be valued for apportionment, and grants banking and financial institutions a monthly optional mechanism to claim part of eligible credit. It lists categories of blocked credits-notably exclusions for most motor vehicles, specified hospitality and insurance-related supplies, construction and works contracts for immovable property, supplies under presumptive schemes, non resident inward supplies (except imports), personal consumption, lost or gifted goods, and specified recovery-related taxes-and empowers the Government to prescribe attribution rules while defining plant and machinery for these purposes.