“The ‘damaged’ vessels were eventually confirmed to be the Ropucha-class tank landing ship Minsk, while the submarine was B-237 Rostov-on-Don, one of Russia’s newest Project 636.3 Improved Kilo diesel-electric attack submarines commissioned on December 30, 2014.”
https://www.popularmechanics.com/military/a45126258/ukraine-destroys-russian-submarine-in-drydock/
“The ‘damaged’ vessels were eventually confirmed to be the Ropucha-class tank landing ship Minsk, while the submarine was B-237 Rostov-on-Don, one of Russia’s newest Project 636.3 Improved Kilo diesel-electric attack submarines commissioned on December 30, 2014.”