That would be a breakthrough, and one that depends entirely on the Pakistani military, but can they do it without CIA and Pentagon backing ? The Indian army in Kashmir is not some foreign expeditionary force in unfamiliar conditions like the Russians were, supply chains are rock solid, they know the conditions, have the lay of the land and that mountainous terrain well.
Pak could try this militarily but I think it will end very badly for the jihadi rebels. Not likely to happen, though, for a number of reasons...
Despite the nasty nature of armed and religious armed conflict, we here in the subcontinent still play a bit of a gentleman's game. This is not a wild jungle like the middle east
where those 3 guys openly support proxies and conflict against one another all over the region.. manpads, improvised rockets, ieds, atgms, armored vehicles, mlrs, beheader jihadis, heart eating jihadis, psycho jihadis.. sab kuch chalega
The Pulwama IED was a big deal as far as rebel capabilities/tactics go this but it is not really an advanced technology. Let's see where this goes..
Geopolitically also, Pakistan will not be able to get away if they supercharge this insurgency. Advanced weapons will be easily traced back, unlike Pakistan, we don't border lawless war ravaged and an 'easy weapons' junkyard like you have to deal with your neighbour, Afghanistan.
Russia will have none of it, China will have none of it (they are very 'hands off' when it comes to the Kashmir issue), Uncle Sam will definitely have none of it, OIC guys have a good economic partnership with India and no disputes with us. Only the craziest "martyrdom" loving retarded jihadis will stick their necks out for such a misadventure.
Again, it's not the middle east.. you are not Turkey or Iraq or Israel etc where Uncle Sam goes along with their regional ambitions where it suits them.
If left to you, would you go that route for ideological reasons anyway ? Think about it, man. If you create a Syria in the valley a lot of people are going to be caught in the crossfire.. we will bring a lot more firepower than the Russians etc have brought into Syria.
In RPG terms, India is like a monster warrior build with all the weapons and armour upgraded, the most powerful squadmates, and nonstop health regeneration (death by thousand cuts attack is weak and will not work). The Kashmir jihadis are a pesky level 1 insects.