Tax deduction for North Eastern undertakings grants full exemption for eligible business profits over a fixed consecutive assessment period. A statutory provision allows a full deduction of profits and gains for eligible undertakings in specified North Eastern States for ten consecutive assessment years beginning with the initial assessment year. It applies to new manufacturing, substantial expansion, or specified eligible businesses begun within the defined period, subject to conditions barring splits, transfers of used machinery and exclusions for certain goods and activities. The section disallows concurrent deductions under listed provisions and adopts applicable procedural provisions from section 80 IA.