Northeast India is the eastern-most region of India. It is connected to East India via a narrow corridor squeezed between independent nations of Bhutanand Bangladesh. It comprises the contiguous Seven Sister States (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura), and the Himalayan state of Sikkim. Except for the Goalpara region of Assam, the rest did not become part of political India until the 19th century and later. TheBrahmaputra valley area of Assam became a part of British India in 1824, with the hill regions annexed later. Sikkim was annexed to the Indian union through a referendum in 1975; it was recognized as part of Northeast India in the 1990s.

Northeast India is generally considered one of the most challenging regions of the country to govern. It has been the site of separatist movements among the tribal peoples, who speak languages related to Tibeto-Burman.

Northeast India constitutes about 8% of India’s size; roughly 3/4th the size of the state of Maharashtra. Its population is approximately 40 million (2011 census), 3.1% of the total Indian population; roughly equal to that of Odisha.

The Siliguri Corridor in West Bengal, with a width of 21 to 40 kilometres (13 to 25 mi), connects the North Eastern region with the main part of India. The region shares more than 4,500 kilometres (2,800 mi) of international border (about 90 per cent of its entire border area) with China (southern Tibet) in the north, Myanmar in the east, Bangladesh in the southwest, and Bhutan to the northwest.[1]

The states are officially recognised under the North Eastern Council (NEC), constituted in 1971 as the acting agency for the development of the eight states. The North Eastern Development Finance Corporation Ltd (NEDFi) was incorporated on 9 August 1995 and the Ministry of Development of North Eastern Region (DoNER) was set up in September 2001.

source- wikipedia