GST exemption for development rights and long term lease premiums enables relief for residential construction, with reverse charge on unbooked units. Amendments provide GST exemptions for transfer of development rights (TDR) or FSI and for upfront amounts for long term land leases used for construction of residential apartments intended for sale, with the exemption amount pro rata to the carpet area of residential apartments. Promoters must pay tax on the proportion attributable to residential apartments that remain un booked on issuance of completion certificate or first occupation on a reverse charge basis, subject to specified caps. Deemed value rules and definitions for apartment, promoter, project, REP, RREP, carpet area and FSI are prescribed; effective 1 April 2019.