This is a wonderful resource article, outlining Soviet Tank Company (Tank Regiments) and Tank Company (Motor Rifle Regiments).

For instance, a Cold War, Soviet Tank Company (Tank Regiment) was Comprised of three Platoons of 3x tanks per platoon.

Tank platoons prior to the late 1980s consisted of a platoon headquarters squad and three tank squads, each consisting of one T-64, T-72 or T-80 tank for 12 personnel and 4 tanks total; platoons that used the older T-54, T-55 or T-62s added another crewmember for a total of 16. However, tank units operating in Eastern Europe began to standardize their platoons to just two tank squads, for a total of 3 tanks and 9 personnel.