Can Russia build 3000 Su-57?
Um, what?
Russia invaded far off lands when they had the capacity, don't think they wouldn't do it again if their economy and population weren't shrinking.
Specifically the 3 major components has to be of the 5th generation - body, engine and radar. The SU-57 body is pretty much there. The radar isn't there yet where it was promised and is required to be (ie. distance, number of tracked items, etc.). The worst situation is with the engine. Russia still doesn't have 5th gen "stealth" engine. What is being flown currently is "4.5" gen - a well improved 4th. You can see it clearly here https://en.wikipedia.org/wiki/File:Sukhoi_T-50_Maksimov.jpg