If the torque converter is completely bad and not creating any torque then yes the bad torque converter could cause no reverse.
But the torque converter when bad would also cause no forward movement either since the torque converter spins only one way when the engine is running.
As you press the gas pedal the torque converter spins faster and then creates movement on the other shaft of the transmission which causes the transmission to move.
If your transmission is not going into reverse then you likely have something wrong inside the transmission such as the reverse gear or reverse bands etc.
A transmission solenoid could also be the culprit or it could mean the automatic transmission needs rebuilt.