Indian Arihant Class Nuclear Ballistic Missile Submarines
Note, this is the indegenous INS SSBN sub, not the new Akula II SSN sub they are leasing from Russia. In addition, the second SSBN sub is coming along:

Indian Defesne Research Wing said:
In a major step towards achieving allround ability to launch nuclear payload from air, land and water, a 83 MWe pressurised water reactor (PWR), was fitted into INS Arihant and trials were conducted. The submarine was launched last year and began its ‘sea acceptance trials’ (SAT) earlier this year wherein it was taken out of the harbour.
With INS Arihant, India has become the sixth country after the US, Russia, China, France and Britain to have succeeded in constructing such a nuclear submarine.
Note, this is the indegenous INS SSBN sub, not the new Akula II SSN sub they are leasing from Russia. In addition, the second SSBN sub is coming along:
The Hindu said:
The Hindu reported that the construction of a second Arihant-class nuclear submarine, to be named INS Aridaman, is moving fast at the Shipbuilding Centre (SBC) in Visakhapatnam. It is slated for launch by this year-end.
“The boat, under outfitting now, is headed for a year-end launch. Meanwhile, hull fabrication is on for the third Arihant-class nuclear-powered ballistic missile submarine,” the sources said. “Unlike surface vessels, submarines are fully outfitted before launch, which makes it a prerequisite for its weapons to be tested and ready well in advance.”
The first submarine of the class, INS Arihant, launched in July 2009, completed its harbour acceptance trials in Janauary and the crucial sea acceptance trials in February.
“This was be followed by weapon trials this summer before the submarine is formally inducted into the Navy, hopefully in 2013, when the country will attain the much-desired nuclear triad,” the sources said. Concurrently, nuclear-powered submarine INS Chakra, borrowed on a 10-year lease from Russia mainly for training purposes, will be inducted in the latter half of 2012.