Scales to Play Over F#5
Every chord is a subset of several scales: any scale that contains all of a chord's tones fits over it. Pick a chord to see the matching scales from its own root, the major keys the chord belongs to, and full fretboard diagrams for every scale on guitar.
A F#5 chord contains the notes F# – C#. Any scale that includes every one of those 2 tones fits over it — from the root F#, that means F# Major, F# Natural Minor, F# Melodic Minor, F# Harmonic Minor, F# Major Pentatonic, F# Minor Pentatonic, F# Blues, F# Rock 'n' Roll, F# Dorian, F# Phrygian, F# Lydian, F# Mixolydian, F# Dorian Bebop, F# Mixolydian Bebop, F# Half Whole Diminished, F# Spanish, F# Gypsy Major and F# Gypsy Minor. Start with the first scale listed: it is the most common choice, and the others color the same chord tones differently.
F#5 is also diatonic to 6 major keys: A major (relative minor F#m), B major (relative minor G#m), C# major (relative minor A#m), D major (relative minor Bm), E major (relative minor C#m), F# major (relative minor D#m). In a song from one of those keys you can also solo with the key's own major scale or its relative minor pentatonic across the whole progression, not just this chord.