The chord F#m/A# that is shown here contains the notes: A#, C#, F#, A. The root of the chord is F# (The lowest sound - the bass - is A#). 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 F#m/A# shown above, place your fingers as follows:
On string number 4 (the thickest), on fret number 3
On string number 3, on fret number 1
On string number 2, on fret number 2
On string number 1 (the thinnest), on fret number 0 (open string)