
Shimano GRX RX600 Crankset
Yes, both the 4iiii PRECISION Shimano GRX RX810 Power Meter and the Stages Shimano GRX RX810 Power Meter are compatible with Shimano GRX RX600 cranksets.
This is because RX810 and RX600 cranksets both use the same interface, which is called Hollowtech II.

4iiii and Stages NDS Power Meter Crank Arms
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.