Real estate GST rate changes reshape apartment taxation, input tax credit reversal, and reverse charge conditions for ongoing projects. Amends the Assam GST rate notification for real estate services by revising tax rates and conditions for construction of affordable and other residential apartments, commercial apartments, and other construction services. The notification prescribes one-time option requirements for ongoing projects, special valuation rules, and separate input tax credit adjustment formulas for REP and RREP projects. It also provides reverse charge treatment for shortfall in procurement from registered suppliers, special rules for cement from unregistered suppliers, and detailed definitions governing real estate project classification and valuation.