The D flat dominant thirteenth chord is a 6-note chord consisting of the notes Db, F, Ab, Cb, Eb and Bb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Db13.
Interactive piano diagram for the D flat dominant thirteenth chord
Chords that are a subset of Db13. These contain less notes but all of them are included in Db13.