Explanation:

1, 3 and 4

Patkai Bum Hills: It is situated India's North-Eastern border with Burma. The word "patkai" means "to cut chicken" in Tai-Ahom language. It is originated by the same tectonic processes that resulted in the formation of the Himalayas in the Mesozoic. These hills are crammed with conical peaks, steep slopes and deep valleys but they are not as rough as the Himalayas. The whole region is surrounded by forests comprising of sandstones.
Naga Hills: It is located in India extending into Myanmar which forms a divide between India and Myanmar.
Mizo Hills: It is formerly called Lushai Hills. It is located to in south-eastern Mizoram state, north-eastern India, forming part of the north Arakan Yoma system.