State GST on specified building materials notified at 6% for listed intra-State supplies, with tariff-based classification rules. State GST of 6 per cent is notified for specified intra-State supplies of goods covered by the Schedule to the notification, including fly ash bricks, fly ash aggregates, fly ash blocks, bricks of fossil meals or similar siliceous earths, building bricks, and earthen or roofing tiles. The notification adopts the tariff classifications and interpretative rules of the Customs Tariff Act, 1975, and gives undefined terms the meanings assigned under the GST enactments. It comes into force on 22 September 2025.