Since PAF is allegedly receiving J-35 ground based fighters in coming years, IAF will feel obliged to purchase stop gap 5th gen fighters until their AMCA reaches IAF service. AMCA looks like it's over 15 years away from IAF service, by their own admission, around 10 years.
They have not even a single known tech demonstrator (assumption) let alone a static test prototype, let alone a flying prototype. Their journalists seem to have confused a plastic + fibreglass + wood mockup with a prototype. What they've displayed is NOT a test product of any sort.
This means they will likely purchase either the Su-57 or F-35 as the only commercially available fighters outside of the J-35 which they can't and won't buy for obvious reasons. F-35 can be sold to India. Certainly more so with Trump and Musk in power. F-35 would be the better choice to purchase even though the strings attached are more substantial than Su-57. IAF F-35s are guaranteed to be permitted to work against China. So for IAF, why not go for the superior combat platform? Even without the networking strengths of F-35, it is still a better BVR fighter than Su-57. Plus if IAF purchases Su-57, China can just buy a minimum order down the line and test and train against it to develop the best tactics to counter it a la UK with France during Falklands wrt Argentine Exocet missiles and Mirages. In that example the UK didn't even have any examples to train against, just the specs.
Considering Su-57 would be totally stupid of India. There's nothing stopping China to buy 24 or maybe even fewer as a modern Su-35. It could even serve the same role Su-35 has served and is serving in PLAAF - opfor training, study, and forward deployed during peacetime to hide mainstay fighter digital signatures.
Oh and the Su-75 is not that much closer to actual service than Indian AMCA is. So... yeah that's not really an option either. KF-21 you may as well buy F-35, similar strings and with F-35, it's much more capable. KAAN is about as an option to India as J-35 is.
Just because a platform is operational and has seen combat doesn't mean it's a good or even a safe option. See the F-104 for example. Americans have the money and numbers to paint over any number of cracks (in the F-35s case, literally).
Also the Russians haven't spent the last 30 years continuously at war like America has. I'd attribute the su-57s sluggish development to the Russian lack of desire. Things have obviously picked up since the Ukraine war. Orders will take years to fulfill. so I'd imagine the Russians may have ironed out any kinks on their flagship jet.
Having said that, the Su-57 is really an option for India. Indians often replace the avionics and various other interfaces on their Russian jets with western ones. I can't imagine the Russians being happy about French or American engineers poking around their planes once in Indian hands. Part of me thinks the reason the Russians bring out the Su-57 demonstrator to the airshows is to say, "look, we can make advanced 5th gen aircraft too, now here's some cheaper jets we want to sell you".
Also, *if* the Su-57 is as good as the Russians claim it is, why wouldn't they be inducting as many of them as they can make for the next 10-15 years? The Russians are swimming in money right now so they aren't exactly looking to making a quick buck.
As to why the Indians won't adopt the F-35? Cost is the obvious one. Not only the initial and maintainance costs. Inducing such an expensive platform could potentially mean the end of many of the joint ventures with Russia. Indians even struggled to make a firearm without Russian assistance. The Americans may be happy to sell F-35 with railguards, but what about nuclear submarines, ballistic missiles, aircraft carriers. etc? Even if they are, can the Indians afford it?
So in sum I don't think either is a good option for India. Best they can do is to sit on their thumbs and hope Pakistan doesn't induct J-35s first; buying either platform will result in that being a fait accompli.
