Russia lost most of his fleet by the collapse of the Soviet Union but even now it represent a formidable adversary today they have 4 types of submarines ready to defend the Mother Land:
Project 941 Oscar Class II (Kursk was of these class), their main objective was to attack Aircraft carrier groups with high precision missiles GRANIT (they carry 24 of them) these weapons are very fast reaching a speed of Mach 2.25, they can evade defense and prioritize their objectives so they can destroy any target in a matter of minutes, they can also carry Nukes of 550 kilotons.
Project 971 AKULA (SHARK in Russian) the most deadly and quietly sub in the fleet, the latest was launched on 2001 named GEPARD, their shape was thank to studies of sea animals like sharks, whales, etc.
Project 941 TYPHOON, the most biggest Boomers of the worlds they can carry 20 SLBM SS-N-20, they are 6 of them.
And the new “toy” of the Army is Yuri Dolgoruki (Project 955) first boat launched on april 15 2007, and other 3 are under construction they are going to use SLBM Bulava R-30 (brother of Topol M) and they are also capable of evading any ABM.
But there are other great project awaiting that is the Project 855 would be also very quiet Boomer and most modern in the Russian NAVY very similar to SEA Wolf of USA Navy.