275/60R20 is 1.77" taller than 285/50R20, a +5.67% change in diameter. That is more than the 3% many tire shops use as a limit, so plan on recalibrating the speedometer and checking ABS and stability control.
Ground clearance changes by 0.89" (half the diameter change), and the tire needs 0.89" more room above it.
285/50R20 is 0.39" wider. On the same wheel offset about half of that, 0.20", moves toward the suspension and half toward the fender.
Both fit a 20" wheel; the sidewall is 0.89" taller on 275/60R20.
Details: 285/50R20 in inches · 275/60R20 in inches · change sizes in the calculator