They include the mountains and plateaus of northern Kashmir, the Himalayas proper and the hills of Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura and Meghalaya.
They are divided into three groups. They are
The Himadri, the Himachal and the Siwalik are three major ranges of the Himalayas.
The Zaskar, the Ladakh and the Karakoram along with their eastern extension, Kailash in Tibet are the trans Himalayan ranges.
Mishmi, Patkoi Bum, Naga, Manipur, Mizo, Tripur, etc. are the hill ranges of Purvachal.