The problem with that is that, given some basic EW competence, the Indian side would be able to detect the PLAAF AWACS emissions and identify it to at least something that does not belong to Pakistan, and can geolocate the source. It won't take long to catch the hand in the cookie jar if you know what I mean.
Well, let’s just got the sake of argument assume EW competence on the Indian part, it’s still nothing like as simple as you seem to think.
If it was that simple to track datalinks, the whole stealth concept would not work. Fifth gens would be able to be located and tracked via their datalinks.
Modern datalinks put huge emphasis on countering even being detected and identified as being datalinks.
You would need to be using seriously obsolete equipment, and/or be making some seriously silly mistakes to allow opfor to geo-locate you via datalinks.
At best, the Indians might be able to detect radio-wave emissions from PLAAF AWACS going into Pakistani airspace, but it would be a major coup for them to be able to ‘prove’ much beyond that. They should certainly not get anything that the PLAAF could not simply brush off with a generic statement like, ‘it’s an AWACS, of course it’s going to be emitting radio waves all over the place!’
And even if they could ‘prove’ that PLAAF AWACS are feeding data to the PAF, well what off it? China is breaking zero international laws flying AWACS in its own airspace; and it can communicate anything it wants to Pakistan.
Short of declaring war on China, India is going to have to just lump it.