You will not be able to see a difference till you drive in each position. Most put the tunes in ascending order. I would just play with it and get a feel of what you think you might have.
Anyone with a ts burner and software can read the chip. You can send it to any ts tuner, but not sure how much they charge to read it.
If you take the chip out, the truck will return to stock unless someone had the pcm flashed too.
Also see how it shifts. if it has harsh shifts, then it most likely has canned tunes. Even though it appears that there are 9 or so positions, only 6 can be used. there should be a washer deal with a finger to drop in one of the holes to adjust how many positions can be accessed.
Hope this helps