the only steroids proven to burn fat in studies are test, anavar, and gh.
in theory any steroid that binds strongly to the AR receptor in muscle also binds to the AR receptor in fat - and hence burns fat.
So tren is probably a good fat burner, although i have read no study that shows this, many users claim it though.
u could add t3/t4, clen, eca or even dnp if you are desperate enough, but cardio at 30 mins a day and lower calories are stil key.