I just finished my custom TARDIS and I wanted to make it the main console room for the tardis I placed, so I did /tardis-interior-pos ~ ~ ~ , exited, then entered, but I was back in the original console room. I tried using specific coordinates but that doesn't work either.

This is a common bug in the Dalek Mod, if you are on the server make sure your key is linked, break the exterior and ask a staff member to force land the Tardis with the key ID and that should work.

If you are on a single player world please inform us so we can send you the command to do it yourself

 Sorry for late reply, I'm on single player.