Chanakyans will always follow the path of aggressive hegemonism. The good news is that Ballistic missile defense system is unreliable and counter technologies have grown by leaps and bounds with far less investment. Even US ballastic missiles won't score 100% hit rate and won't be able to defend all their military installations and cities from a nuclear attack. India is a zillion years behind. BMD is astronomically expensive and in order to counter a sophisticated missile force it would require a large enough no. to put up a face saving show.
PAK needs to invest in offensive technologies like Cruise missiles, countermeasures such as chaff and flares, reduced RCS etc. These will be much cheaper alternative and will render the Indian BMD useless while milking them dry. Besides India borders PAK and reaction time to incoming PAK attack will be next to impossible.