Concessional SGST for exploration and production supplies allowed subject to DGH certification, transfer rules and disposal depreciation conditions. A concessional Tripura SGST rate applies to intra State supplies of goods in the annexed List used for petroleum exploration, production and coal bed methane operations under specified licences, leases or contracts, limiting state tax to the amount calculated at the concessional rate. Eligibility requires a DGH certificate at the time of supply; subcontractors must produce additional affidavit and principal's undertaking. Transfers need DGH transfer certification and undertakings, and disposals may be taxed on depreciated value computed by a prescribed straight line quarterly schedule.