Question: how arunachal became part of india?
Answer: Renaming. The North-East Frontier Agency was renamed as Arunachal Pradesh by Sri Bibhabasu Das Shastri, the Director of Research and K.A.A. Raja, the Chief Commissioner of Arunachal Pradesh on 20 January 1972, and it became a union territory. Arunachal Pradesh became a state on 20 February 1987.