Scales to Play Over Dm6
Every chord is a subset of several scales: any scale that contains all of a chord's tones fits over it. Pick a chord to see the matching scales from its own root, the major keys the chord belongs to, and full fretboard diagrams for every scale on guitar.
A Dm6 chord contains the notes D – F – A – B. Any scale that includes every one of those 4 tones fits over it — from the root D, that means D Melodic Minor, D Rock 'n' Roll, D Dorian, D Dorian Bebop, D Half Whole Diminished and D Gypsy Major. Start with the first scale listed: it is the most common choice, and the others color the same chord tones differently.
Dm6 is also diatonic to one major key: C major (relative minor Am). In a song from one of those keys you can also solo with the key's own major scale or its relative minor pentatonic across the whole progression, not just this chord.