Arunachal Pradesh (part of India)
British Nationality could be obtained through your birth, or through the birth of any one of your parents or grandparents, in India. This arises because of Britain's relationship with India and its Colonial history. India includes the disputed territory Arunachal Pradesh, which is also claimed by the People's Republic of China as part of South Tibet).
To determine what form of British Nationality you might have, an analysis of your family's history must be done, and then applying it to the Nationality laws of India that were passed over the years.
STATUS OF INDIA
Up until 14.08.1947, the territory now known as India fell within the Crown’s Dominions as British India.
The 560 Princely States (which occupied two thirds of British India) were until various dates between 1947 and 1949 British Protected States.
From 15.08.1947 to 31.12.1948, British India (but excluding British Baluchistan, East Bengal, North-West Province, Sind and West Punjab and Burma) came with the Crown’s Dominions as the Dominion of India.
On 01.01.1949 (at which time Pakistan and what is now Bangladesh became independent) and up to the present day, India was an independent Commonwealth country.