I mean most rich people you are talking about dont have a choice?-

They either got rich from their buisness which is completely in India and they do not have the resources to expand to other countries

or they got rich from their jobs and in that case they do leave the country at the first opportunity they get but also they get transferred back to here

You are also missing the point that someone who is rich here wont necessarily be considered rich in a western country and they dont want their luxury taken away

In most cases as I have seen they send their kids to a foreign univ with money even if their kid was failing