Arunachal Pradesh formerly known as North-East Frontier State or North-East Frontier Agency is a state in northeast India. It is an integral part of India but after the government shift from British Raj to Republic of India, NEFA was declared as a state again on 20 February 1987. Itanagar is its capital and largest town. It borders the Indian states of Assam and Nā¦Arunachal Pradesh formerly known as North-East Frontier State or North-East Frontier Agency is a state in northeast India. It is an integral part of India but after the government shift from British Raj to Republic of India, NEFA was declared as a state again on 20 February 1987. Itanagar is its capital and largest town. It borders the Indian states of Assam and Nagaland to the south. It shares international borders with Bhutan in the west, Myanmar in the east, and a disputed 1,129 km border with China's Tibet Autonomous Region in the north at the McMahon Line. Arunachal Pradesh is claimed in its entirety by China as South Tibet as part of the Tibet Autonomous Region; China occupied some regions of Arunachal Pradesh in 1962 but later withdrew its forces.