UTGST rates for real estate supplies: differentiated rates, project-wise ITC transition rules, reverse charge and one-time option requirements. The amendment prescribes differentiated UTGST rates for construction and related works in REP and RREP, sets project-wise transitional ITC calculations (Tx and Te) based on aggregate ITC, carpet area, booking, invoicing and percentage completion, requires separate computation for tax components, mandates reporting and payment for shortfalls from unregistered suppliers including reverse charge treatment for certain inputs, and provides a one-time electoral mechanism for promoters to opt into alternate tax rates with specified procedural requirements.