Air Defenses we need at present scenario:
1)Anti-Ballistic missile defense
2)Theater defense like S-400 protecting large portion of area's.
3)Area protection like cities,towns near border with Medium range SAM's like Barak's and Akash missile system
4)Bases,fuel dumps,ammunition dumps must be protected by point defense like iron dome and pantsir S-1 because they are the most attacked when war broke's out.
5)While on move Pantsir S-1 will be god for protecting the advancing armor and infantry.
There is no true anti ballistic missile system. Most of the systems are not foolproof. Only short range missiles can be intercepted.
S400 is imported. We need PDV or Ashwin which is improvised. With Israeli seekers, it is possible. Even BARAK-8 is said to be ABM, though it is neither confirmed nor denied.
SAMs are not for area protection but for protection against cruise missiles and aircraft. They are to be deployed near borders against airspace violations. We don't just protect 1 city from airspace violations but entire border. SAMs actually make interceptors jobless. We don't need interceptor planes due to SAMs. SAMs also takes out cruise missiles, subsonic and even Brahmos type (mind you that aircrafts travel at 2Mach and are maneuverable. So, 3Mach non maneuverable brahmos is not a big deal).
After putting in SAMs across borders, the only other thing needed for bases, fuel dumps are ABM protection. If cruise missiles or planes can't get in the border, they can't hit bases either. The best way to defend fuel dump, factory, ammunition depots is by making them behind mountains, in the valley or even as a tunnel or underground bunkers
We already developed QRSAM using Astra missile reengineering. With Israeli seekers, they should work absolutely awesome