B m6/C
The B m6 chord consists of the B (Perfect unison), D (Minor third), F# (Perfect fifth) and G# (Major sixth) notes, with C as the bass note.

How to play the B m6/C chord
- Play C as the lowest bass note in the left hand
- Find B (Root) on the piano keyboard
- Add D (Minor third) — 3 semitones above B
- Add F# (Perfect fifth) — 7 semitones above B
- Add G# (Major sixth) — 9 semitones above B
- Press all 5 notes simultaneously to sound the B m6/C chord