The only towable RVs I've found without brakes have been small tent trailers and the smallest and lightest of popups with GVWR well under 2000 pounds. Even these have a brake option, which will have been ordered by the original selling dealer if located where the state has a low threshold on "trailer brakes required."
I don't think you will find a TT sold anywhere with 4000-5000 pound GVWR that goes not have electric brakes and a breakaway activation. You might find much lighter TTs occasionally with surge brakes, but not at a weight that requires breakaway braking.