you can get the best compatible B350 MoBo for that R5 3600. After updating it to the latest BIOS of course.
Hardware Unboxed have tested it on Asrock's AB350M Pro4 and they didnt even gone thru the R5 3600 as the R7 3700X reports around 33 to 47 C in the VRMs area.
some downside of putting the R5 3600 on the AB350M pro4 is RAM speed is apparently limited to 3000mhz, which is weird as when they tested the R9 3900X and R7 3700X, they managed to run all of their test at 3200mhz RAM.... but they're greeted with a BSOD when they tried the blender test at 3200mhz ram with the R5 3600.
performance difference between X570 and B350 is little to none from their testing when using the R5 3600.
of course, if you want to be sure then get a decent B450 mobo.