No matter how you look at it, Pakistan can inflict serious damage on India in the event of a nuclear exchange. Shouldn't it be top priority for India to erect a multi-layer defense shield against the potential threat?
A unilateral plan based on untested technology is not the best way to go about this. There has to be a comprehensive approach, which contrary to standard Indian belief isn't "optional." Sometimes you have orchestrate multiple objectives at a time knowing that one will not work without the other.
If numerous calamities and terrorist attacks have shown anything is that the greatest source of confusion, morbidity and mortality is the lack of infrastructure, not just in the physical sense but also in terms of a proficient emergency service and disaster recovery system. Less than a year ago, South Bombay, the defacto financial, cultural and economic capital of India was left burning for days on end because there was no set protocol to address large scale emergencies, and by large scale I mean what 10 well trained Pakistani terrorists could unleash in a matter of hours.
No amount of ballistic missile shields based on endless computer simulations are going to help prevent a grand scale catastrophe if basic social services can't be dispensed by proficient governmental authorities. There is an urgent need for not only multiple layers of ABMs, but also things like fire departments, police units, EMS, etc etc who operate with the assistance of state of the art technology designed around their operational fields.