The last C-17 produced by Boeing has yet to find a buyer and India has indicated that it is keen to buy the cargo plane.
The final white tail (P-272) has been sold to Qatar who will reportedly take delivery some time in 2017. So no, there are no white tails available for India.
If they really wanted 3 I am sure the State Department could spring a couple from the DoD. The C-5 upgrade program can more than fill any hole.
Umm, no. The State Department does not make these decisions. And while the C-5 upgrade program does improve the C-5, it does not make a C-5 into anything like a C-17. So no, no number of C-5Ms could fill the holes created by giving USAF C-17s to India.