To avoid confusion for other readers about the term Zodiac as it is usually associated with the famous circular zodiac of the Hator Temple Dendera in the Louvre: That circular zodiac is from a small penthouse room on top of the temple roof. The zodiac I'm talking about here is the rectangular zodiac in the entry hall (Hypostyle) where it is split in two parts on the furthest right and furthest left row on the ceiling. The complete entry hall ceiling is drawn here on Pl.18:

[digitalcollections.nypl.org]
Denderah [Dandara] (Tentyris). Plafond du portique du Grand Temple.
Jomard, M. (Edme-François), 1777-1862 (Editor)
Napoleon I, Emperor of the French, 1769-1821 (Associated name)
Paris, Impr. impériale, 1817

The zodiac constellations are in the two parts depicted in each of the upper row of the two, in the following order from Nut's head to toe written:
* Capricorn Sagittarius Scorpio Libra Virgo Leo Scarab-Crab
* Aquarius Pisces Aries Taurus Gemini Scarab-Crab

The Scarab-Crab stands outside of this upper row.

What's missing there of the 12? Yes, Cancer. And the position at the Scarab-Crab would be correct for Cancer.

Sirius is Sothis standing in front of Anukis (water pourer), both on the 2-person barque between Gemini and Scarab-Crab, directly next to the sun-rays.