When Volition Reins enters the battlefield, if enchanted permanent is tapped, untap it.
You control enchanted permanent.
1/1/2011 Volition Reins may target and may enchant an untapped permanent.
1/1/2011 If the enchanted permanent is untapped as Volition Reins enters the battlefield, the triggered ability won’t trigger at all.
1/1/2011 Gaining control of a permanent doesn’t cause you to gain control of any Auras or Equipment attached to it.