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.
Alert 5 » India wants to buy last ?white tail? Boeing C-17 - Military Aviation News
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. India had wanted to buy three more aircraft to add to its existing fleet of 10 C-17s but Boeing closed the production line before India could get its act together.