Depends on what you include here to avionics. The radar will mainly be Russian, most likely the IRST and the HMS too, but all other EW sensors in FGFA should be sourced from India itself, or from western partners. Also I highly doubt IAF will except an external LDP like the Russians seems to have in mind.
Secondly, SPECTRA EWS is basically a 5th generation systems, since it offers similar capabilities as the F22 or F35 systems too, not to mention that the Israelis are replacing US avionics on their F35s with Israeli techs, so they are available today.
The Russians have pretty good relations to Israel and France, not to mention that we have done similar with the MKI or the Mig 29s too, so I don't see a problem on that side either.