Cold war TO&E for a soviet tank regiment was 95 in three 31 tank battalions.
The Russian Army is not able to field many pure tank regiments or even mechanized brigades right now. They lack the trained manpower and sufficient modern equipment for it. So they send in picked battalion-strength units to back up local rebels who do most of the actual fighting while the Russians occupy and pretend they aren’t actually participating in the war.
In the last war, the Ukrainians pulled off an actual operational tank offensive in brigade strength.