A. North eastern Hills:- North eastern Hills are made up of Patkai , naga and Mizo Hills. these hills are mainly composed of strong sand stones.
Patkai and allied mountain ranges run along the Indo-Bangladesh-Burma border . These ranges forming an arc must have come into existence along with the Himalayas.
(b)Naga hills:- Naga hills reaching a height of around 3825 meters, lie on the border of India and Myanmar. These hills are part of a complex mountain system, and the parts of the mountain ranges inside the Indian Nagaland are called Naga hills.
(c)Mizo Hills:- Mizo Hills rise to about 7,000 feet and their slopes are covered with thick evergreen forest containing valuable timber and bamboo.It covers Mizoram.