Concessional duty eligibility for manufacturers requires mandatory registration before availing notification-based exemption benefits. Concessional duty rules apply to manufacturers intending to avail a notification granting duty exemption when goods are used for the specified purpose; unregistered manufacturers, including makers of exempted or non-excisable goods, become eligible to claim the benefit only after obtaining registration under the Central Excise Rules, making registration a precondition to the notification-based exemption.