Caste separation?!! This is an event of the Government of India. If it had done anything to separate castes like that, they would have a tough time with India's Supreme Court. People would be in uproar. All caste discrimination in India involves private matters, between and amongst citizens, not amongst the Government and the people(except in very far-flung places where the law doesn't hold much of a grip).
Those are probably partitioned reservations for Army, AF and Navy personnel and their families. Public viewing areas are much larger, and follow the length of the road near the beginning.
I thought the photo was Bhutan. And was quiet surprised to see such a military there.