India becomes the sixth country in the world to operate a nuclear-powered submarine.
The INS 'Chakra II' was to be formally commissioned into its navy at its Visakhapatnam (VEE-SHA-KA-PAT-NAM) base late on Wednesday.
The Chakra II is an 8,000 tonne Russian-built Akula II-class submarine leased by India's navy.
It is the first nuclear powered submarine to be operated by India since it decommissioned a similar vessel used for training navy personnel.
India is also developing its own nuclear-powered submarine.
The sub is powered by a nuclear reactor, but does not carry nuclear weapons in accordance with international non-proliferation treaties.
Construction of the warship first began in 1993, but was delayed for about a decade due to lack of funds.
The five other countries to have nuclear powered submarines deployed are the UK, China, France, the US and Russia.
Travis Brecher, Reuters
