Both Samsung Galaxy NX and Canon R6 have 20.0 MP resolution sensors but Samsung Galaxy NX's sensor is APS-C (23.5 x 15.7 mm ) and Canon R6's sensor is Full frame (36 x 24 mm ).
Since Canon R6's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Samsung Galaxy NX.
Below you can see the Galaxy NX and R6 sensor size comparison.
As seen above, Canon R6 has a 2.3x Larger sensor area than Samsung Galaxy NX. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.