Tax exemption on intra-state supply of specified used motor vehicles limits state tax to margin-based rates. Exempts state tax on intra state supplies of specified categories of old and used motor vehicles by taxing only the supplier's margin at prescribed state tax rates per vehicle category. Vehicle categories are defined by fuel/type, engine capacity, length and ground clearance. For suppliers who claimed depreciation under income tax law, margin equals consideration received less depreciated value; otherwise margin equals selling price less purchase price; negative margins are ignored. Exemption is inapplicable where the supplier has availed input tax credit, CENVAT, VAT input credit or equivalent taxes. The notification is effective from the stated January 2018 date.