wth is Agni 6? and if we have a 8,000 ICBM any target in China can be within reach from even places like Tamil Nadu Orissa maybe even the Nicobar islands
Not exactly.
Agni-3 (3,500 KM) / K-4 (All 4 Nuclear Submarine Arihant series)
Agni V (5,000 KM) / K-5 (All 4 Nuclear Submarine Arihant series)
Agni- VI (6,000-7,000 KM)
Our MIRV was not ready for Agni V till 6 months back, It is 95% ready but not ready for induction/production. MIRV will be inducted in both Agni V and Agni VI also K-4,5 but 1st most likely in Agni-VI. Hence, Agni V would be tested without MIRV later Agni VI with MIRV. Also, Agni VI will carry more payloads and MIRV too. Later on, Agni V will also have MIRV. K-4,K-5 both will have MIRV.
As far as China, Our Nuke Submarine from Bay of Bengal (K-4,5 will cover whole Chine) + Agni V MIRV from northern Part + Agni VI from Southern part.
Pakistan already covered long back. 2nd Strike Capability K-15(Arabian Sea) and K-4 MIRV will be covered from Bay of Bengal too.
Hope it's Clear. As far as 10,000-16,000 KM (name not yet decided) - it would be come in inventory after 2015. It's matter of time only. Money, technology and Capability we already have and no threat from Europe, US too. So Slowly and Gradually