F 6/C
The F 6 chord consists of the F (Perfect unison), A (Major third), C (Perfect fifth) and D (Major sixth) notes, with C as the bass note.

How to play the F 6/C chord
- Play C as the lowest bass note in the left hand
- Find F (Root) on the piano keyboard
- Add A (Major third) — 4 semitones above F
- Add C (Perfect fifth) — 7 semitones above F
- Add D (Major sixth) — 9 semitones above F
- Press all 5 notes simultaneously to sound the F 6/C chord