As per section 10(26) of the Income Tax Act, a member of a Scheduled Tribe residing in any area specified in the Sixth Schedule of the Constitution or in Arunachal Pradesh, Manipur, Mizoram, Nagaland and Tripura is exempted from paying tax on any income that accrues from any source in the area or state.
There may be item Unit specific exemption. You need to study of the area and other industries there. Be a member of Trade Association after you start a unit.