I am an NRI living in USA. If I send money (<
$15000) in a year to my father in India as a gift to buy home in India under his name, will there be any tax implications in India for him or in USA for me ?
Gifts under $15K (total per calendar year) to one person are not subject to US gift tax (which in the US is imposed on the giver, not the recipient, of the gift). As for your father in India, this is a gift from a close relative and thus is free of any tax on the recipient. There can be a problem of you don't send the money via normal banking channels (including transfer services such as Xoom or Transferwise or Money2India or Remit2India etc) and instead use the illegal hawala system of transferring money.