The Ai (also Abor) is a major collective tribe living in the Himalayan hills of Arunachal Pradesh (in northeastern India), and they are found in the temperate and sub-tropical regions within the districts of West Siang, East Siang, Upper Siang, Upper Subansiri and Dibang Valley. The older term Abor is a deprecated exonym from Assamese meaning 'those who cannot be controlled'. Some of them are found in Southern Tibet, around areas near the Indian border. The literary meaning of "Adi" is the Hill or mountain, which was used to unification term used to identify people of Minyong, Galo, Pasi Padam, Bori, Bokar, Karko, Milang and Ramo sub tribe as a single tribe. Of Proto-Austronesian and Tibetan stock, they speak a language belonging to the Tibeto-Burman family. However, their traditions believed them to be the lost descendants of the Tatars and Abo-Tani(Abo- Father; Tani- Man).