The chord F/Gb that is shown here contains the notes: Gb, C, F, A. The root of the chord is F (The lowest sound - the bass - is GB). The scale from which the chord is derived is Major, and the degrees of the scale are: 1, 3, 5.
To play the chord F/Gb shown above, place your fingers as follows:
On string number 6 (the thickest), on fret number 2 with finger number 2 (middle finger)
On string number 5, on fret number 3 with finger number 3 (ring finger)
On string number 4, on fret number 3 with finger number 4 (pinky)
On string number 3, on fret number 2 with finger number 1 (index finger)
Start strumming from string number 6 (notice not to play strings 1 and 2).