Check out our 2022 comparative overview post on World ballistic missile boats.
Simpo / Gorae class SSB (Ballistic missile conventionally powered submarine) (1 active or used as a test platform) LOA ca. 225′ / 68.6 m TDISP 1,600 tons submerged (estimate)
Romeo class attack submarines LOA 251′ / 76.5 m TDISP 1,800 tons submerged (originally up to 22 transferred, many as Chinese made kits, most now out of service)
Sang-O class coastal submarines LOA 115′ / 35.1 m TDISP 370 tons submerged (about 40 in service, 1 unit captured by South Korea)