The Indian Navy will induct a Russian-built Akula-II-class Nerpa K-152 nuclear submarine into its fleet in early 2012.
The second submarine, which will be rechristened as INS Chakra, was leased by the Indian Navy in a move to enhance the country's defence capabilities.
The ten-year lease follows a $650m accord between India and Russia, signed in January 2004, to lease the 110m-long, 8,140t submarine Nerpa.
Capable of remaining underwater for months, the vessel will bridge the operational gap until the commissioning of the indigenously built nuclear submarine INS Arihant for the Indian Navy.
The nuclear-powered submarine emits very low levels of sound while operating underwater making it difficult to detect by enemy warships and helicopters.
The Akula-II-class submarines have a strike range of 3,000km and are armed with 28 nuclear-capable cruise missiles, whereas the Indian version is expected to be integrated with the 300km Club nuclear-capable missiles.
Indian naval teams have been undergoing training on the nuclear-powered submarine for several months.
Russia is currently modernising the 45,000t aircraft carrier INS Vikramaditya, formerly Adm Gorshkov, at the Shemash shipyard for the Indian Navy; it is expected to join the Indian fleet in early 2013.
Presently, India possesses a conventional diesel-electric submarine fleet, which includes four German HDW submarines and ten Russian-origin Kilo-class vessels.
India is also planning to procure an additional 40 Russian fly-by-wire Sukhoi-30 heavy-combat jets.