Real estate GST: specified state tax rates, ITC allocation formulas and reverse charge rules for construction services take effect. Amends Kerala GST notification to prescribe state tax rates and conditions for construction-related services in REPs and RREPs, distinguishing concessional rates for affordable housing and higher rates for other residential and commercial apartments, and introducing an elective higher-rate option for ongoing projects. It prescribes project-wise methods to compute eligible input tax credit (Te) and reversal/payable amount (Tx) with factor-based formulae, mandates an 80% procurement threshold from registered suppliers (with reverse-charge rules and exceptions), sets reporting/payment procedures and expands definitions to determine applicability and valuation. Effective 1 April 2019.