You tend to have those, considering the complex nature of India’s enemies- domestic and foreign, and their modes and terrains of operation.
one thing I find fascinating is the Special Frontier Force, raised primarily from ethnic Tibetans. Originally a guerilla force which fought the Chinese and smuggled the Dalai Lama out of Tibet, its current status is quite mysterious, but it seems to be a self contained army within the larger Indian Army, with its own intelligence, aviation, and Special Operations units.