Yes, India should have been a Nuclear power. Unfortunately, India tested in 1974 and this treaty came about in 1968 so India missed by a few years. Also, then India was aligned with Russia to some extent and did not have enough voice then. I feel if the countries then had seen India rising like the way it did in 90s, they would have decided to make India a NPT signatory with Nuclear Weapon status.
I feel, with this exceptional treaty, maybe in future, India will get to finally get in the club as Nuclear Weapon country.