I have a Woods BH750 and use it on my 36HP tractor.
IMO, according to info I got from Tractordata.com a B6200 with 12.5 PTO HP is too small for a BH750.
If you mount the BH750 on the B6200 3 pt. the BH750 requires a tractor with a minimum lift capacity of 800lb at 24". The B6200 rear lift at 24" is only 705lbs.
B6200 weight is 1223 lbs. BH750 is about 800 lbs. Mounting a BH750 would make the B6200 front end too light.
A BH650 might work but I'd suggest it be mounted to a sub frame not 3 pt. mounted.
Not sure of the size difference between the Woods 650 & 750, but I have the 650 on my B7200d and it does just fine. Dug out a few stumps this fall with no problems.