What will be the gift tax to me, if I gift my father about 50k in India. My Father is in India and an Indian Citizen.

Just to be clear, you're talking about a gift of 50K rupees, or about $830 USD, right? My understanding is that gifts between blood relatives in India are not taxable.

If it is $50,000 USD, you would have to file a U.S. gift tax return, but no gift tax would be due by applying part of the Unified Credit to offset the tax.

This advice assumes you are a U.S. Citizen or green card holder.