I agree with Zigner that any defamation action taken against a resident of India would need to be commenced in India.
In India, defamation can be charged as a crime (with fines and up to two years in jail possible) or pursued as a civil action.
Defamation defenses in Indian civil actions include the defense of truth (which is the same as with US defamation laws) but truth is not an absolute defense to defamation under India's criminal laws. There have been efforts underway for years to have the criminal defamation laws in India repealed (as they have been, for the most part, in the US), but the efforts to date have failed.
There are other significant differences between the laws of India and the US - including what is considered defamatory and when defamatory statements are actionable. Slanderous statements (spoken defamation), for example, is rarely actionable in India.
So, if what has been published about you is defamatory under Indian laws, you will need to consult with a lawyer in India or an international law attorney in the US who is well-versed in the defamation laws there.