I have removed the tile from by shower floor along with the drain. I then realized that the drain is not centered in the shower stall, it is off by one inch from center. The stall is on a concrete slab and the pipe is a 2" cast iron, I know they make off sets for toilets, but just wondering if they make something that would work for my situation. I wanted to use a pre-fabricated pan which of course requires that the drain be centered, but again in my case I am off by one inch. Any assistance would be greatly appreciated.

It ain't going to happen without spending lots of time breaking concrete.

Doug is bang on. To move that cast iron raiser over you will have to break up the cement and move the entire trap and raiser the only other option would be to install a custom tile shower. Good luck, Tom