IMO the Indians aren't as hopeless as people here believe, but that's only because the PLA is screwing up. If the InAF wants to do it, they can launch a massive alpha strike on all PLA airbases near the border using their long-ranged missiles. Then, with air defense crippled in the short-term, they can bomb PLA positions while advancing ground troops.
The PLA is stuck with two uncomfortable options:
#1, it can shoot down Su-30MKIs as they come in for the strike run, but the Su-30MKIs would come down over Indian airspace. Global opinion would be quite negative to China.
#2, it can take the damage.
The PLA is only stuck in this position for the following reasons:
#1, the PLA isn't fielding sufficient air defenses in the region to block the InAF. A sufficient volume of HQ-9s and similar SAM systems with anti-missile capability can stop Indian cruise missiles in their tracks.
#2, the PLA is moving too many assets too close to the border. Hotan airbase is an example; Hotan is within strike range of the Su-30MKI / Brahmos-A aircraft missile combo without Su-30MKIs having to violate Chinese airspace. Yet, for whatever reason, the PLAAF moved two J-20s in. The J-20s might be untouchable (or nearly so) by the InAF's assets in the air, but once they're on the ground they're sitting ducks for Indian munitions. Remember, a Fw 190 from WW2 can destroy an F-22--all it needs is that the F-22 is on the ground and the Fw 190 is in the air.
A serious PLA attempt to engage the InAF would either be a full air defense, with hundreds of anti-cruise missile systems at each air base, or a second-strike capability, wherein the Chinese forces assigned to the border function as bait, while a more substantial force sits to their rear, ready to reinforce and punish the InA / InAF if they try something.
