Russia's navy has around 300.000 tons worth of active ships. (and by active i mean those which are undergoing refit as well) I did projections for china in 2015 and it came out around 350.000 tons. perhaps today it's ten or twenty thousnad tons less, but not more than that.Russian Navy have a largest tonnage but less operationnal.
Those numbers don't include submarines or minewarfare vessels or transport ships.
Tonnage wise, its USA>China>Russia>Japan.