The F sixth/ninth chord is a 5-note chord consisting of the notes F, A, C, D and G.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as F6/9.
Chords that are a superset of F6/9. The chords include more notes but always F, A, C, D and G.
Chords that are a subset of F6/9. These contain less notes but all of them are included in F6/9.
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 F6/9 chord. Feel free to save or share the image as needed.