Ricoh GXR A16 24-85mm F3.5-5.5 has a 16.0MP APS-C (23.6 x 15.7 mm ) sized CMOS sensor and features Smooth Imaging Engine IV processor. On the other hand, Sony A6600 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor.
Sony A6600's sensor provides 8MP more than Ricoh GXR A16 24-85mm F3.5-5.5's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the GXR A16 24-85mm F3.5-5.5 and A6600 sensor size comparison.
Ricoh GXR A16 24-85mm F3.5-5.5 and Sony A6600 have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.