F m7/A#
The F m7 chord consists of the F (Perfect unison), G# (Minor third), C (Perfect fifth) and D# (Minor seventh) notes, with A# as the bass note.

How to play the F m7/A# chord
- Play A# as the lowest bass note in the left hand
- Find F (Root) on the piano keyboard
- Add G# (Minor third) — 3 semitones above F
- Add C (Perfect fifth) — 7 semitones above F
- Add D# (Minor seventh) — 10 semitones above F
- Press all 5 notes simultaneously to sound the F m7/A# chord