6-Bromodione is a fast acting competitive inhibitor of the aromatase enzyme. It works by binding to the aromatase enzyme to prevent it from aromatizing androgens. This is not a permanent binding and later acts to normalize aromatase (and thus estrogen levels) as hormone production returns to normal. It specifically targets aromatase and does not act as a central anti-androgen like some other post cycle products can. This means that your libido and mood will not be negatively affected.
I found "6-bromoandrostenedione vs. 6 Bromodione" and says: "They are the same thing; I think it also goes by "6-bromolane. I would imagine that products containing 6-bromodione would be a mixture of alpha and beta, given the expense associated with separation. Also, 6-alpha-bromodione should convert into 6-alpha-bromo-testosterone, which should be a relatively potent anabolic steroid. So, if taken for PCT, it could actually be suppressive (like epistane, which is both an AI and suppressive steroid). Actually, I bet 6-alpha-bromodione would make a decent PH.
6-beta-Bromodione works in a similar way but has an irreversible and permanent effect. This works well to mediate the excess aromatase that was produced while on cycle, while the alpha isomer works to normalize the natural levels. The goal is again to transition into normal production levels for all hormones affected by the anabolic cycle.