The A flat sixth/ninth chord is a 5-note chord consisting of the notes Ab, C, Eb, F and Bb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Ab6/9.
Chords that are a superset of Ab6/9. The chords include more notes but always Ab, C, Eb, F and Bb.
Chords that are a subset of Ab6/9. These contain less notes but all of them are included in Ab6/9.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Ab6/9 chord. Feel free to save or share the image as needed.