The Tripura Land Revenue and Land Reforms Act,1960
Section 187. Special Provision regarding Scheduled Tribes
No transfer of land by a person who is a member of the Scheduled Tribes shall be valid unless,-
(a) The transfer is to another member of the Scheduled Tribes; or
(b) Where the transfer is to a person who is not a member of any such tribe, it is made with the previous permission in writing of the Collector; or
(c) The transfer is by way of mortgage to a co-operative society.