We are funding the MKI MLU already, even AMCA. All we gotta do it customise the Su-57 with pretty much the same avionics. The MKIsation costs are not a lot since we only need to adapt existing tech to the FGFA's internals. So we get a deal done by 2025-26, it's gonna be a 6-year effort to get our first two jets, with most of the 60 jets available by 2035, in time to meet the Chinese 6th gen.
Of course, we can screw all that and just buy the Russian one with basic customisation, like we did with the Rafales. Either case, it will enter service between 2030-35 and will serve our high end needs until the MKI replacement comes along by 2050.
Anyway, this is only if the IAF believes the Rafale isn't good enough for the job. 2025 to 2040 is way too long to have a capability hole. And there's a good chance even AMCA might not match up to the Chinese 6th gen. So the risk goes all the way to 2050.
Why do we always talk about the Future
The problems are "Here ,Right Now "
As if PLAAF J 20 was not enough
now we have PAF J 10 too
Has The IAF taken a PLEDGE not to buy anything but F 4 RAFALE