There have also been instances where people have fought against each other for some reason or the other but such cases do break out in all countries, so India being a niche of such diversity can be excused for once!
India won't be India if not for this diversity. If India means Kanchivaram sadi then India also means Pashmina shawl. If India means extreme hot climate of the south India, then India also means the snow covered mountains of the north India. If India means the desert of Rajasthan then India also means the highest rainfall grounds of Assam!
Such diversity is also found in the school of minds, where one stands for the motion, another stands against it. This means an added advantage, because while one is looking at the positive aspects of a side, other is hunting for the counterpart negatives.
The diversity of India has a great edge over the plain unanimously joint countries! It might be speculated that is just another starry eyed optimist opinion, but then if we didn't differ wouldn't we be non-Indians