Sony A6300 has a 24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features BIONZ X processor. On the other hand, Sony RX10 III has a 20.0MP 1" (13.2 x 8.8 mm ) sized BSI-CMOS sensor and features Bionz X processor.
Below you can see the A6300 and RX10 III sensor size comparison.
As seen above, Sony A6300 has a 3.2x Larger sensor area than Sony RX10 III. 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.