Once S-400 is active, most of your ballistic & cruise missiles are easy targets, with 2 full scale regiments and hundreds of missiles enforcing a virtual no fly zone over Pak. Major cities like Mumbai, Delhi etc. have already started recieving phase-1 home made BMD elements in enough numbers to shoot down any misses from the S-400. Nuke armed cruise missiles will be shot down by the likes of Spyder-SAM, Akash etc. The chance that your first shots with the NASR on the battlefield or any other missile will be shot down.
As for other means such as using the Falcons for nuke bombing, again they face the likes of MKI, potentially plenty of Rafales, plenty of SAMs and many other tricks.
Worst part is Pak will have to use it nukes on its own soil and still be nuked for using them. True, there is no vedic shield protecting us, just layers and layers of quite capable SAMs.