Commencement provisions set a staged entry into force for major fiscal provisions, with remaining sections activated by government notification. The Finance Act, 2021 enacts measures to implement the Central Government's financial proposals and sets a two-tier commencement regime: a principal block of sections comes into force on the Act's stated commencement date, while a separate block of sections comes into force on such date as the Central Government may appoint by notification in the Official Gazette, preserving executive notification power for staged commencement of specified provisions.