The attachment options will determine the hole pattern you want in mounting the holster to your belt. None means it doesn’t come with the hanger. Bladetech, Boss, springer, rht pattern means the hole pattern which will work for the specific hanger you’re going to use. By specifying which mounting option (Boss/bladtech etc), rht will drill the holes in the kydex for use with the mounting option you’re going to use.
For my TSO, I opted for None (I already have the Boss hanger on hand), for hole pattern, I choose bladetch because it matches the hole pattern for the Boss hanger I’m going to use to mount the holster to my belt.
Heres a couple of pictures of my RHT holster with the thumbrest option.
This setup with the optic mount actually fits into the holster after some dremel mod.