Tile on top of Laminate flooring?

If tile is a self stick tile with a sheen then yes you must remove. Because you have a slab underneath, it would be best to use that as your substrate and can install tile directly over the slab. If you have a tile that needs to be waxed periodically, then you can take your chances with going directly over them. Ask at the floor store if there is an adhesive that will adhere to that particular type of tile. Do remove the toilet, and you will want to replace the wax ring as well. Take a picture with you of the floor to the floor store, good luck.