Setting custom resolutions:
If any of the resolutions, supported by your GPU/Monitor doesn't appear on options, then editing the "config.ini" found in "%:\Users\User name\Documents\CAPCOM\RESIDENT EVIL 6" will do the trick.
Set the custom resolution as shown below:
[DISPLAY]
Resolution= WidthxHeight [Set the custom resolution here]
Aspect=DEFAULT But you must set it to 16:9/16:10/4:3 depending on the resolution you choose or the resolution might change automatically.
RefreshRate= Set it to your monitor's refresh rate.
FullScreen=ON [Sometimes, setting it to "OFF" will work and change to fullscreen after opening the game]
Save the file and close it. Right click on config.ini and select properties. Enable Read-only and apply.
The game should work fine now. Any resolutions above 640x360 worked. Setting resolutions below 640x360 reverted it back to 640x480.
Border less Window mode:
Set Fullscreen=OFF as shown above. Download any Fullscreenizer tool [Any fullscreen tool may work, but I've only tested this tool: "http://runtimelegend.com:3110/badsector/fullscreenizer" which works perfectly] and after opening the game, fullscreenize it and you're good to go.
Border less window gives much clearer image if you use any resolution lower than your monitor's native resolution. Also, by this way- you can run the game in resolutions that your monitor or GPU don't support.
Removing cinema scopes during cut-scenes:
Big thanks to Helifax for his RE6 plugin. Use Widescreen Fixer.
After selecting Resident Evil 6 plugin, go to options [The little Cog icon beside plugin name] select game's version. Disable "Automatically Detect Resolution". In "Display count" set the number to what it was before disabling Automatically Detect Resolution.
In the "Uncorrected Resolution" section, set the resolution to the one that you selected for your game. And then save settings. The cinema scope [black bars on top and bottom] from all the cut-scenes will be removed except the 2 pre-rendered cutscenes.