Your Right the Chinese ICBM are better. They were designed to challenge America. and built during the Cold war. That is expected.
The Nag and Arjun are already inducted.
If you actually want to know What is going on with Arjun
Indian MoD outlines roadmap for MBT Arjun, Mark II in pipeline | Frontier India Strategic and Defence - News, Analysis, Opinion - Aviation, Military, Commodity, Energy, Transportation, Conflict, Environment, Intelligence, Internal Security
As far as the Agni series is concerned.
As of 2008, the Agni missile family comprises three deployed variants:AGNI-1,2 and 3
1. Agni-I short range ballistic missile, 700 - 800 km range.
2. Agni-II medium range ballistic missile, 2,000 - 3,500 km range.
3. Agni-III intermediate range ballistic missile, 3,500 - 5,500 km
range.
4. There will not be an Agni-IV missile, with DRDO leapfrogging from intermediate range Agni-III to a standard ICBM possibly.
5. Agni-V intercontinental ballistic missile, 5,000 - 6,000 km range (under development).
Yes, The Agni-2 failed the end user trial. Which was meant to test manufacturing quality. Obviously something went a miss but People are working to solve the Manufacturing issues. And the next time the Agni-II is tested successfully we would know they did it.
so unless India going to be attacked in the next month of 2, i think we are fine.