I want to install a 2-piece Toto toilet with a rough-in dimension of 12 inches to replace an existing 2-piece Kohler toilet. The dimension from the face of the tile that subsequently got added to the wall is presently at about 11-1/2 inches to the center of the bolts holding down the toilet.

What latitude if any can be safely assumed in the rough-in dimension (+/- inches) given by the manufacturer?

Are there other solutions short of having to get a toilet with a 10 inch rough-in dimension which will result in a large gap between the tank and the wall?

Thanks

You can scoot the closet bolts forward a quarter of an inch if you need to, then dry set the toilet to be sure you have the required clearance before setting it with a wax gasket(s).