Installing DBA slotted rear rotors on GU wag.
Changing out rotors/pads F/R. On rear rotor there is of course the wheel stud holes and hub hole, plus 2 x say 4mm threaded thru holes to assist removal of rotor from axle. And the one in question, the 12 mm (approx) plane thru hole on a slightly larger PCD than wheel studs holes (same as stock).

Question: Is this 12mm hole in rotor to align up with the single blind hole in axle end face for alignment purposes or opposite for balance?

Should have observed where the position of the genuine rotors were before removal.

John