Concessional excise on specified tobacco products requires reinvestment of the concession amount into the Northeast within a prescribed period. Concessional excise duty applies to specified tobacco products made by Northeast units set up under the New Industrial Policy, excluding cigarettes, biris, cut tobacco and smoking mixtures, and does not exempt National Calamity Contingent Duty. The concession is subject to a condition that the manufacturer invest an amount at least equal to the duty concession in plant and machinery in the Northeast within the prescribed period and retain it for the lock in term; a designated committee will monitor compliance and failure to invest requires repayment with interest under the Central Excise Act.