Watch the Adding The 6th online guitar lesson by Jason Loughlin from Blues Connections: Minor
The major 6th can also be thought of as a 13th as they're both the same pitch. Though, without spelling the extensions underneath the 13th (b7th, 9th, 11th) it sounds like a 6th over a minor blues. One of those harmonic phenomena.
Let's add the major 6th into the minor pentatonic scale. It's located a whole step higher than the 5th or a half-step lower than the b7th. We'll build this across a single string so you can see the intervallic relationships. Learn these new scales in A minor, D minor, and E minor.