Yes, the Stages Shimano GRX RX810 Power Meter is compatible with both the Shimano GRX RX810 and GRX RX600 cranksets, as they both use the exact same interface.
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 10 mm of clearance for Stages 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.