I have noticed in general, and it may not be true in this case, that Indian boys tend to be spoiled.
He needs to see a psychologist. Now.
Could this be a simple case of spoiling?
Could you give some idea of the dynamics in the house, you have given us a list of his behaviors ,has he got siblings, does anyone else around him, family or baby sitters, upset him, do they yell ,could he have seen and be copying this behavior, yopu say from 2 years old, has his family had a Doctor check him out to see if there is any obvious problem .you say he 'beats his Mom and Dad ,do they allow him to do that,? perhaps he should have some boundaries set , time outs have been known to work.Firtsly with this 4 year old it may be a good idea to find out WHY he is doing this , 'he does not sit properly to eat or drink' in what way, what is it he gets angry about can you give us an instance ..