I looked through some stuff and looked online but didn't see anything with 12. Usually it's 10 or 11 depending on whether it is the perfect Tree of Life, the imperfect Tree of Life, or the combined Tree of Life. Perfect has Da'ath but not Malkuth. Imperfect has Malkuth, but not Da'ath. Combined has both.

Some depictions of the Tree of Life include extra circles at the top above Kether or at the bottom below Malkuth.

Above Kether, those are "the three veils of the absolute" aka "the three negative veils of existence: Ain, Ain Soph, and Ain Soph Aur.

Sometimes Qlipoth is tacked on to the bottom below Malkuth. That's not a Sephirah.