Both Nikon W300 and Nikon S6500 have 16.0 MP resolution sensors but Nikon W300's sensor is 1/2.3 (6.17 x 4.55 mm ) and Nikon S6500's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Nikon S6500'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 Nikon W300.
Below you can see the W300 and S6500 sensor size comparison.
Nikon W300 and Nikon S6500 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture.