Please I would like to know what could be responsible for an imbalance in the phase to phase winding resistance of a 0.75kW 3 phase induction motor.

The readings are
RY - 22.8 ohms
YB - 23.0 and
RB - 22.8 ohms.

What can be done to correct this imbalance?

 

I would consider these values to be normal variation in winding resistance. Why do you feel that it needs to be corrected?

 

that is a minor variation say 10turns or so for a motor of that size, are you having a problem with the motor?