Re: Report says Pak may launch nukes against India
You oversimplify.
what makes you think that all the forces will be at a same place at the same time. Nuclear bombs will be effective only if they are dropped on a populas city.
You don’t need to annihilate all the opposing troops. You simply need to disrupt their ability to execute offensive or defensive operations. Armies can only carry out such activities through massing troops. For example, to attack a town , you may need to commit 15000 troops. If they attack , they are going to be coming from, say, 1 direction, along a 12 kilometer front. You can use a pattern of 10-15 low yield warheads to saturate this front with a nuclear barrage and thereby eliminate a large protion of those 15000 attacking troops.
Nuclear bombs are much more effectively used for attacking battalion sized and larger units than they are for attacking cities. Attacking a city will not help prevent your land from being captured.
Or to eliminate the leader ship/nuclear command and control of other nation. once you eliminate later two then you disintrigate the remaining leadership
Both India and Pakistan have been frantically developing the infrastructure required to maintain command and control in a nuclearised war, using theories developed for this situation by NATO and the Warsaw pact. Trust me and my sources on that 
again to remind you that both countries (atleast india) has capability of NBC warefare. So war will not be a short one unless usa or russia intervenes.
NBC capability allows troops to fight on battlefields contaminated by radioactivity and biological/chemical agents. It also makes them invulnerable to biological/chemical agents. But no one has invented anything that can protect a human being from a nuclear detonation.
plus now days wars are more fought by missiles and airplanes and army is used to occupy the land
Only if you are the USA. No other country, be it India, Pakistan, Russia, the UK, France or China, has the missile capacity and air power required to do so.
The last modern conflict that didn’t involve the USA was the Falklands war - and that was a classical conventional conflict.