The mount on your lens appears to be the one used by the Rolleiflex SL35 line of cameras. Rollei couldn’t be bothered to give the mount a name, so it’s unofficially known as the Quick Bayonet Mount (QBM).
The mount locks using a notched tab (A) when turned clockwise. Other common mounts that lock using a notched tab include Minolta SR/MC/MD and Contax/Yashica (C/Y). To differentiate them, it’s necessary to note the types and positions of other lens-camera linkages.
For QBM, auto aperture is controlled by a pin (B). Aperture setting for TTL metering is communicated to the camera via a tab (C).