The turret was crashed with the curvic locked. This caused the rotateable face, which was locked to the stationary chassis via the 2 or 3 piece curvic, to force the curvic to move within the play of the heads of the socket head cap screws that hold it. If the alignment pins were still in, then they are damaged as well.
If the alignment pins were not in, then this is an adjustment. If they were in, then this is a repair.
Please do not "shim" the turret, as the problem is not that you are out in Y...the problem is that you have a misalignment of a rotation that appears as if it is out in Y (and in X, as well)
Use the alignment instructions that are in the service manual for a puma 240, located in the thread that has all my manuals.