Every fingering that fits a hand
x30046
easy
x30343
moderate
x3034x
easy · no 5
8a888a
moderate · barre
x30346
hard · no 5
What is true of it
Cm9 is C, E♭, G, B♭ and D — 1, b3, 5, b7 and 9 counted from C.
On an instrument that cannot reach all 5, the 5 and 1 go first, in that order.
The easiest of the 5 fingerings below is x30046: 3 fingers, held at the 3rd fret.
None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.
1 of the 5 need a barre.
1 string stays silent.
Where its notes are on the neck
The brass dots are C, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
Cm9/E♭
x60046
Cm9/G
310043
Cm9/B♭
630043
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.