piano chord
C♯m7
C♯1E♭3G♯5B♭7
Minor triad with a minor seventh. The same four notes as a major sixth chord a third above.
Written the other way round it is D♭m7 — the same twelve keys on a piano, a different piece of notation.
What is true of it
C♯m7 is C♯, E, G♯ and B — 1, b3, 5 and b7 counted from C♯.
These are also the notes of E6/C♯. Which name is right depends on what is underneath and what came before — the notes alone do not decide.
On an instrument that cannot reach all 4, the 5 goes first, in that order.