1. Have your game installed on the internal SSD. This is required for Protontricks to see the game. It may be possible to force Protontricks to scan SD card too, but I didn't look into it.

1. Download Resident Evil 6 FusionFix from Github: Resident Evil 6 FusionFix[github.com]
2. Extract it. There should be dinput8.dll file and scripts folder.
3. Move everything to the root folder of Resident Evil 6 ( where the game .exe is located). You can find this folder by simply clicking right mouse button on RE6 in your Steam library, then selecting manage and browse local files.
4. Install Protontricks through Discover Store and open it.
5. Click on Resident Evil 6 and click ok. The window will close and another one will pop-up after ~10 seconds
6. Select "Select the default wineprefix" and click ok
7. Select "Run winecfg". Another window will pop-up
8. At the top of the new window, click on "Libraries" tab. Under "New override for library" from the drop-down menu select dinput8 and then click Add button. The dinput8 will appear in the box under the "Existing overrides". Click Ok
9. Close Protontricks and open the game to check the results
10. Enjoy the game in its glorious form