Every fingering that fits a hand
300066
easy
300331
moderate
300363
moderate
300365
moderate
300366
moderate
What is true of it
Gm9 is G, B♭, D, F and A — 1, b3, 5, b7 and 9 counted from G.
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 300066: 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.
Where its notes are on the neck
The brass dots are G, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
Gm9/B♭
600063
Gm9/D
x50365
Gm9/F
100333
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.