What do you mean with you can't set the tardis interior position? Like don't you do know the command, does it give you a error? Can we have more info about your probem?
I know the command I put it in but it just wont let me go to that interior
Is this on single player or multiplayer? Because the command sometimes has a bug where to fix it you must remove the exterior and replace it with the same ID (or place down a new exterior and set the pos to that interior)
I fixed it please lock the thread and it was on singleplayer