The drain for the toilet was installed incorrectly. It will cause the toilet to be 6" off the wall.

Who did this install? Totally wrong and should know better if they are going to be working on plumbing, make them redo it correctlu, usually 12"

What is the situation here, basement, wooden floor with ceiling below? What kind of pipe? That far off, I don't see any reasonable fix except go in cut the drain pipe and do it right.