not sure I understand the question. you have the obvious ones like Struve but of course it is also relative to the division. nowadays there are 6'3 lightweights whereas back in the day you would see 5'9, 240 pound dudes like Jeff Monson. so it's all relative to division and time frame. Also for example Nate Diaz is tall for his division but would be nothing special from MW upwards. i'd say, roughly the cutoff point for "tall" per division is:
FW 5'8
LW 5'11
WW 6'1
MW 6'3
LHW 6'5
HW 6'5
of course, those are just numbers I pulled out of my ass and don't necessarly make sense.