Aid or cash is irrelevant. The supply chain runs through various parts of the United states. The cost of buying + maintaining the F-35 are enormous, far more than your most expensive fighters like the Su-30 and Rafale. India would have to build very specific infrastructure costing billions to make sure the F-35s are housed properly and are being maintained to a certain standard.
The US can literally hold all of that hostage.
You can pretend India is capable of handling all of this, but even the Indian government doesn't think it can't, which is why the F-35 has been rejected in the past as well.
It's very clear you have a basic misunderstanding of how geopolitics works, as you're constantly making comments that sound more nationalistic than realistic.