Rawls' A Theory of Justice is relevant to just about everyone, and perhaps India most of all, because India contains so many of the world's poorest and most disadvantaged people.
The core message of A Theory of Justice is that we should conceive of justice as if we were reasoning from behind a "veil of ignorance", where we did not know who we were or what part of society we would end up in. We might end up rich or poor; we might end up men or women; we might end up White or Black, Brahmin or Dalit. So we should try to construct a society that is minmax, that is, where the minimum standard of life is maximized. That way, even if we end up being put in the most disadvantaged group, we will still have a good life.
Of course, in practice we do know what status we have. We are not behind a "veil of ignorance". But this central idea of trying to maximize the welfare of those at the bottom, those who are most disadvantaged, is a very compelling one.
And the most disadvantaged in India are very disadvantaged indeed. 29% of the population---some 370 million people, more than the entire population of the United States---is below the national poverty line, which is set at a nominal income of as little as $0.44 per day. Even once you adjust for purchasing power, most of these people live below the UN poverty level of $2 per day. Add to that the rampant discrimination against women and remnants of the caste system, and life as, say, a Dalit woman in a poor rural village is living an extremely disadvantaged life.
If Rawls is right---and I think he basically is---then this is a grave injustice. India, as well as other countries, should be trying to raise the standard of living of these very poorest people, even if it means sacrificing some wealth for those of us at higher standards of living. In many cases it will not; most discrimination is not actually economically efficient, and removing it would make life better for almost everyone. But in some cases it might, and Rawls argues that it is our responsibility to do it anyway---that it is morally wrong for us to continue to live so rich while leaving so many others so poor.