The chord G#m/Gb that is shown here contains the notes: Gb, B, Eb, Ab. The root of the chord is G# (The lowest sound - the bass - is GB). The scale from which the chord is derived is Minor triad (1–♭3–5), and the degrees of the scale are: 1, ♭3, 5.
To play the chord G#m/Gb shown above, place your fingers as follows:
On string number 4, on fret number 4 with finger number 1 (index finger)
On string number 3, on fret number 4 with finger number 1 (index finger)
On string number 2, on fret number 4 with finger number 1 (index finger)
On string number 1 (the thinnest), on fret number 4 with finger number 1 (index finger)
Finger numer 1 presses multiple strings as a barre.
Start strumming from string number 4 (notice not to play strings 5 and 6).