The E flat major thirteenth chord is a 6-note chord consisting of the notes Eb, G, Bb, D, F and C.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Ebmaj13.
Interactive piano diagram for the E flat major thirteenth chord
Chords that are a subset of Ebmaj13. These contain less notes but all of them are included in Ebmaj13.