What scales go with a B7M chord?
first of all, it should be BM7, which means "b major seventh". the chord is spelled B D# F# A# and so since it is a major chord it fits right in to the B major scale (B C# D# E F# G# A#). that's the short of it, anyway
I wonder why guitar pro lists it as B7M weird
That would depend entirely on the progression.
What are the notes in the chord? Your incorrect notation makes me think you mean Bmaj7, but you may mean B7 which is completely different.