Margin-based state tax exemption for intra-state supplies of old and used motor vehicles subject to specified classifications and conditions. Exempts the state tax on intra-state supplies of specified old and used motor vehicles by limiting taxable value to the supplier's margin, with different margin-based tax rates for defined vehicle categories; vehicle specifications follow the Motor Vehicles Act, 1988. Margin is computed as consideration less depreciated value for registered persons who claimed income-tax depreciation, or as selling price less purchase price otherwise, with negative margins ignored. Exemption does not apply where input tax credit, CENVAT or VAT input credit has been availed.