Yes, the 4iiii PRECISION Shimano GRX RX810 Power Meter is compatible with all Shimano GRX cranksets including GRX RX600.
Please note, these power meters attach a sensor to the inside of the left crank arm. On some bikes, there is not enough room between the left crank arm and the chainstay for the sensor to clear the frame. Therefore, you should make sure you have at least 8 mm of clearance for 4iiii PRECISION 3 power meters. Also, please make sure that you don’t have a bottom bracket mounted rear brake (used on some aero and TT bikes). Please refer to the image below.