Hi.
You could have a empty game object centered and on paddle hit, get the paddle x position and the empty game object x position.
then do a float operator (paddle x - empty game object x)
When result is higher than 0, its in the right side and when less its on the left.
for 0 you should set to go right or left (your choice) not both.
or you could set a center and for example greater than -1 and less than 1 could be centered.
you can even use the float to manipulate the torque as you have now a distance from center value