The design process on the T-10 began in 1944. It was officially retired from service in 1996.
https://www.tanks-encyclopedia.com/c.../ussr/T-10.php
They were allocated to independent tank battalions.
According to Wikipedia, "It is estimated that some 6,000 Soviet heavy tanks were built after the end of World War II,
of which 1,439 were T-10s."
Presumably, most of the others were JS-3's, mentioned up-thread.
-