Ballistic missile defences are suicidal for India.
Many countries has much higher yield bombs than what they have ever tested.
All these cities will get AAD, PDV protection. AD1, AD2 will come soon. S400 and S500 may zlso be deployed. These cities will be among most protected after US cities from medium to long range missiles.
MIRV, MARV and a variety of first strike options negate any ballistic missile defence system's feasibility. That's something the US and Russia acknowledged a long time ago. Missile defence systems are dangerous for the stability of the region.
Forget advanced technologies. All Pakistan needs to do is simply launch more nukes at once.
See this scenario:
Pakistan wants to launch 100 nukes at India, so India makes a super missile shield over the whole country. This super shield has a 70% interception rate against Medium Range Ballistic Missiles, an astonishing technological achievement.
Pakistan, in a panicked response, starts ramping up its nuclear production to 50 nukes a year. Now in a decapitation strike, Pakistan will launch 200 nukes at India. At this rate, 60 nukes will still slip through and give India a bad day but it may still survive, just set back a hundred years or so.
After a few years, Ababeel is operationalised with MIRV. This brings the interception rate down to 60%. 192 of 320 nukes pass through.
Then after 10 years, MARV is operationalised as well. This brings the interception rate down to 50%. 410 of 820 nukes pass through. All major cities and towns in India will be gone, the Ganges plain where most population centres are is as good as gone forever. South India might be lucky and merely be sent back to the stone age. Not even the Andaman and Nicobar islands will be spared. Rebuilding India through this much radiation and destruction will be impossible.
After 15-20 years Hypersonics come into play, and the interception rate plummets dramatically, probably to less than 5%. Now you have 1000+ nukes successfully attacking India which will surely leave no chance of any life surviving in the region again.
If you had not started a nuclear arms race, there would only be a few hundred nukes at Pakistan's normal production rate of 10 a year minus tactical nukes. Now, you have forced Pakistan to develop extreme offensive capabilities and a huge nuclear stockpile.
Can't even imagine highly populated metros like Mumbai and Delhi getting nuked.... It will be a blood bath......
Mumbai condition will be worst.... It's a small island with huge population density people won't even get a chance to leave town before attack as Mumbai connected with 2 or 3 only bridges to mainland and these exit points will be flooded with traffic and get choked and then imagine a nuclear strike in this situation.....
But I doubt any Pakistan leader will be capable of taking such a bold decision.... For talking we would nuke you is easy but implementing it is a different story... It requires a mentality like Hitler, nadir Shah or changez Khan...
As after such attack world reaction will be a disastrous for Pakistan.... It will be even more isolated compared to North Korea and also maybe responsible nuclear powers like USA, UK, France will be forced to attack and destroy all the nuclear capacity of Pakistan forever....
No, Pakistan's policy is very clear - if you attack Pakistan and cross a red line, you will be destroyed. The world is not going to antagonize Pakistan because India was foolish enough to cross this red line.