Are these ceramic or rubberised type tiles?
If the former they are messy and time consuming to remove, and require a hammer drill with chisel attachment, and cause dust everywhere. If rubberised, they are easy to remove, but the sticky adhesive residue removal is also time consuming. If they don't cover the whole area, a cheat would be to use floor leveller*, hardboard or plywood to make up the untiled area, and carpet over the lot. In both cases I would level the floor to the existing tile level, and carpet over it. For many years, my hall and living room was carpeted over the existing rubberised tiles, with hardboard over an area in a small extension to level it, and it now has wood flooring laid over the same tiles.
I have done all of the above!
* There are some excellent floor levelling compounds available. I can't remember the last one I used, but it mixed up and laid very easily, and gave a perfect finish.