T-64 can be identified by its exhaust vent in the rear, and smaller roadwheels if compared with T-72.
Shadow of Chernobyl Edit
One derelict T-64 can be seen in the area of the Freedom HQ in Army Warehouses, another one can be found near the merc outpost. More can be seen recently destroyed on the road to the Chernobyl NPP, used by the military to reach the center. It is also possible that these tanks were used by the Monolith during the defense of the station, as one destroyed tank has Monolith corpses hanging from the wreck.
In Clear Sky, the same T-64s found in the Army warehouses are seen here. A footlocker containing a loaded RPG-7u can also be located near it.