A useful starting point is to assume that the key of any given song or progression is usually the same as the first or last note/chord of said song or progression. This would indicate Gm for the progression stated above.

Assuming that "Dis m" and "Ais m" are meant to be D#m and A#m respectively, all of the root notes to the chords in your progression are found in the G natural minor scale. This would then imply the key of Gm.

__________________