Civil strife in India in an area located between Assam and Burma resulted in the rebels calling their 'country' by the name Nagaland. No legitimate nation ever recognized this struggle for independence, which began soon after India became a nation in 1947 and extended central control over all regions. Open conflict occurred between 1956 until cease fire in 1964.
The British Philatelic Association gave their opinion that the Rebels issued many "stamps" for political purposes only, and any Nagaland issues should be treated as Propaganda labels, or if desired, Civil War Propaganda labels.
The rebels claimed these stamps were valid for internal postage and frequently used by supporters for independence. It is possible that they were used secretly by supporters. However, during the period of all of these Nagaland issues, the Indian Post Office provided local and international service with stamps from India. Anyone known to support or use the Nagaland stamps would have been severely punished for disloyalty to India.
SOSSI Journal, Volume 21, Number 2, February 1972
SOSSI Journal, Volume 21, Number 4, April 1972