It depends on how much you let your stuttering hold you back. With a mild stutter I see no reason why you wouldn't be able to become a real estate agent. I know stuttering lawyers, notary's, salesmen and CEO's. If they can work in those professions with a stutter I don't see why you can't become a real estate agent. If however you have alot of speech anxiety it could be a problem to be in a profession that requires you to talk all the time every day at work.