Clipper circuits, voltage across voltage divider
The two resistors form a voltage divider - the voltage at the junction between them will be half the supply voltage, unless the battery and diode have an effect.
Since the supply voltage is a 10 V peak sine wave, the junction of the two 10K resistors cannot rise above 5 volts, so the 6 volt battery and diode will have no effect on the operation.
The voltage across Rl will be a 5 V peak-to-peak sine wave.