Krishna
I suspect that the minimal replies are due to there not being a great deal anyone here may be able to offer you in any sort of positive way. Your Dad's Doctors are the only ones with a true picture of what is happening with your Dad.

Clinical trials are occuring in a number of different places, for a number of different drugs. I understand and empathize the desperation and grasping for any positive things, and I enourage you to keep positive thoughts, but the logistics involved in getting your Father from India, into the U.S. and then onto a clinical trial would be complex and time consuming. It may simply be time that he does not have.

You and your Dad are in my thoughts and prayers. I wish I had a more positive message for you
Wayne