India is to formally commission a nuclear submarine into its navy, joining an elite group of nations with similar capabilities.
The $1bn (£630m) Russian-built Nerpa has been leased by the Indian navy for the next 10 years. It was handed over to India in eastern Russia in January.
India previously had a Soviet submarine but decommissioned it in 1991.
It now rejoins China, Russia, the US, the UK and France as an operator of underwater nuclear vessels.
India is also developing its own nuclear-powered submarine which is expected to be ready by the end of this year.
'Pride of Indian navy'
The 8,140-tonne Akula II submarine, the K-152 Nerpa, has been renamed by India as the INS Chakra II.
The submarine will be formally inducted into the navy by the country's defence minister, AK Antony, at a ceremony in Vishakhapatnam, on India's east coast off the Bay of Bengal on Wednesday morning.
The submarine set sail from the Russian port of Vladivostok 40 days ago and is now set to become the pride of the Indian navy, the BBC's Sanjoy Majumder reports from Vishakhapatnam.
In keeping with non-proliferation treaties, the submarine will not be equipped with nuclear weapons.
India had previously leased a nuclear submarine from the Russians in the late 1980s which was used to train its naval personnel.
The INS Chakra will, however, be operational and is expected to give the Indian navy an added advantage, our correspondent says.
It was due to be handed over to Delhi in 2009 but was delayed because of problems during testing.
In November 2008, at least 20 people died in an accident on the Nerpa when a fire extinguishing system was activated by mistake.
India is also building an indigenous nuclear submarine, the Arihant, which is expected to join the navy some time next year.
Russia is also expected to help India train the crew that will operate Arihant.
India and Russia are long-time allies and Russia supplies 70% of India's military hardware.