I think the situation is as followed: India attacks or strikes certain areas inside Pakistan.
Pakistan sees this coming and quickly acts upon it and goes into Indian territory and tries to take out important strategic assets while trying to defend its own airspace, that's the PAF doctrine.
However, then we will have another response from India, and again, Pakistan will not sit back and continue with her activities aswell, so it goes back and forth untill both nations have reached their limits.
I think a war will most likely be a limited one, a few strikes here and there just across the border from both sides, some tough talk from both nations, and afterwards, the international community and especially the U.S. putting a leash on both countries, and the situation de-escalates.
Both nations have to realize, using nukes will destroy their credibility and their reputation in the international community, thus severely affecting the relationships and that will work into both countries economy and so fort, a chain of events will occur.
Anyhow, I think both nations have sensible leaders who will never let things escalate so far to a point where the nukes will be polished and pointed at eachothers major cities.
It's a deterrent, and only a deterrent, similar to a sleeping bulldog that scares outsides or trespasers but doesn't harm them as long as they keep out of sight.