Nothing on Major Scale specially PLAAF ..
Only thing they are busy upgrading defenses around there airbases and infrastructure in TAR..
Which is precisely what we must also be doing and at a much faster rate than present. We currently lack road networks sufficient enough to mobilize massive number of armour in the mountains.
For a successful combat in the Himalayas, we will need to focus on the following things:
1- Military grade roads capable of transporting light tanks and wheeled MGS equipment fast to the forward positions, apart from medical and food supplies to the troops.
2- 95% availability rate of the ALGs that border Tibet which may include the landing ability for C-17 and C-130Js for rapid tactical deployment of crack teams.
3- A planned, structured and multi-layered air defense system, which can take out bombers and fighter jets before they cross the border. And excess of it. Even if it is short range ADS like Akash that is cheap, reliable, rugged and can be rapidly deployed.
4- A multi-tier mountain artillery unit capable of deploying 107mm and as well as 120+mm artillery guns to the hot zones during a conflict.
5- Lastly but most important, a decisive government that can take strong action against an aggressor without getting into political dramas and internal cheap politics.
6- And full autonomy to engage an invading aggressor as required without civilian meddling.
More than the variety of equipment, in a conflict of Himalayan nature, a strong and steady logistics structure other than a decisive government and a fully autonomous military command (during conflict) is necessary for optimum results which can ensure that the conflict doesn't transform into a war of attrition on our side at least.