Bruce wayne is not real. However, in concept, sure. Given the right amount of tech, training and wealth a human being could be come a real life batman (closer to the Dark Knight Trilogy and maybe the Burton series) but no justice league. There are quite a few comic book charecters that poeple could take inspiration from and be a real version of them.
Batman (gadgets, martial arts training wealth....all these millionaires and no one has become batman yet)
Daredevil (a blind man trained in martial arts since childhood, sure..its possible)
Punisher (thats far to easy, just get any trained soldier enough rescources, weapons and a vendetta)
Nick Furry, (just an elite spy with guns...film version that is with out the infinity serum)
Nightwing (an acrobat or gyminst trained in martial arts, yea, its possible, especially Bojutsu or Kali)