2.5 slots will fit in this case, so standard 6800xt, but expect the fans to be right up against the grills, possibly touching, will be noisy.
6800 is a 2 slot in standard form, fits fine, nice and quiet.
Nvidia wise the EVGA XC3 is the one to go for, the 3080 and 3090 are 2.2 slots, so will fit...