I'm 5'11" and my pegs are about the middle. I believe there are two more notches forward they can go, so you should have room. Send them a message and ask them before you commit.
I am also 5' 11" and have my Rivco pegs to the "second to last" extended position. Love 'em. I think your inseam may be more important than your height? I'm a 32".