The most obvious way that they have taken different paths is in the kinds of government that they have had.
India has always been a democracy that has been more or less open to all of its people. South Africa has been somewhat similar to this in that it has always been democratic. However, for much of its existence its democracy was very incomplete as it oppressed the majority of its population through the apartheid system. Egypt and Iran have never been democratic in any true sense. Iran was ruled first by a monarch and then by a theocracy. Egypt was ruled by a series of authoritarian leaders who suppressed democracy.