The E minor thirteenth chord is a 6-note chord consisting of the notes E, G, B, D, F# and C#.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Em13.
Chords that are a subset of Em13. These contain less notes but all of them are included in Em13.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Em13 chord. Feel free to save or share the image as needed.