that is also impossible .
in the indo-china scenario, if PLAAF want to attack, her bomber just need to flew to tibet launch the cruise missiles and then go back, almost air-combat free.
however, if IA want to do some real damage on China. she needs to flew across Tibet and then launch the cruise missiles, that is at least 1000KM from india border. in this case, intercepters can leave if they are run out of ammo, but the escorts can never leave the bombers. eventually the escorts will run out of ammo and can only acts as decoys of the bombers.
on the other hand, if PLAAF decided to intercept the imcomming planes at all cost, no more hit and run. then most likely, this will turn into a dog fight. in this case, tactics and quantity is much much more imortant than quality.
I dont know how your scenerio is plausable. Tibet is a free area to fly in expecially if your flying at high altitudes, and the intercept time for Inaf would be far less. Those bombers would either get shot down or the cruise missiles will. If the Inaf dicided to strike the PLA the would in Tibet cutting apart their supply line. You seem to assume the PLA would have it easy when it come to air warfare against India.
The PLAAF wont resort to an offensive because much of their time would be left on the offensive because of Tibet and the high altitude. If the PLA wanted to strike India, they would with ballistic missiles. The one thing that is sure to work.
You assume things that are wrong. You assumed PLAAF can sustian operations easily in Tibet when in reality they are hampered with quantity! So how are they going to use there advantage? If the Inaf dicid to escalate the war they can bring the fight to Tibet but the reverse is nearly impossible infact sucidal given the friendly home front advantage of the Inaf.
And what makes you thing the PLAAF will be an offensive air force? when was the last time they droped bombs like the Inaf did to Pakistan in 1971 and Kargil?