Go to this link https://github.com/alphanu1/MME4CRT/blob/master/README.md
towards the bottom of the page is the most comonly used resolution. These will be the ones you need to change.
Change the first number to your supper resolution For the list below. and set your HZ to either 50 or 60 exact.
512 x 240 @ 50.006977 SNESpal
512 x 224 @ 50.006977 SNESpal
512 x 448 @ 50.006977 SNESpal
512 x 240 @ 60.098812 SNESntsc
512 x 224 @ 60.098812 SNESntsc
512 x 448 @ 60.098812 SNESntsc
256 x 240 @ 50.006977 SNESpal
256 x 448 @ 50.006977 SNESpal
256 x 240 @ 60.098812 SNESntsc
256 x 448 @ 60.098812 SNESntsc
320 x 240 @ 59.922745 MDntsc
320 x 448 @ 59.922745 MDntp
320 x 480 @ 59.922745 MDntsc
256 x 192 @ 59.922745 MDntsc
320 x 224 @ 59.922745 MDntsc
256 x 224 @ 59.922745 MDntsc
320 x 288 @ 49.701458 MDpal
320 x 576 @ 49.701458 MDpal
256 x 192 @ 49.701458 MDpal
320 x 224 @ 49.701458 MDpal
320 x 240 @ 49.701458 MDpal
320 x 448 @ 49.701458 MDpal
320 x 480 @ 49.701458 MDpal
256 x 224 @ 49.701458 MDpal
256 x 288 @ 49.701458 MSYSpal
256 x 240 @ 60.098812 NESntsc
256 x 240 @ 50.006977 NESpal
640 x 480 @ 60.130001 N64ntsc
640 x 237 @ 60.130001 N64ntsc
640 x 240 @ 60.130001 N64ntsc
640 x 480 @ 50.000000 N64pal
640 x 576 @ 50.000000 n64pal
640 x 288 @ 50.000000 n64pal
256 x 252 @ 49.759998 PSXpal
384 x 252 @ 49.759998 PSXpal
640 x 540 @ 49.759998 PSXpal
320 x 252 @ 49.759998 PSXpal
640 x 252 @ 49.759998 PSXpal
384 x 240 @ 59.941002 PSXntsc
256 x 480 @ 59.941002 PSXntsc
352 x 240 @ 59.820000 Saturn/SGFX_NTSCp
704 x 240 @ 59.820000 SaturnNTSCp
352 x 480 @ 59.820000 SaturnNTSCi
704 x 480 @ 59.820000 SaturnNTSCi
352 x 288 @ 49.701458 SaturnPALp
704 x 288 @ 49.701458 SaturnPALp
352 x 576 @ 49.701458 SaturnPALi
704 x 576 @ 49.701458 SaturnPALi
240 x 160 @ 59.730000 GBA
320 x 200 @ 60.000000 Doom
// Arcade
400 x 254 @ 54.706841 MK
384 x 224 @ 59.637405 CPS1