In my opinion, an academy cannot make you pass the examinations, however they do help in brushing up your skills and providing a good launching pad towards the preparation. Also teachers are available in the academy who can evaluate your paper attempting techniques especially that of the Essay paper, provided you take the pains of solving past papars and showing them to the subject teachers. Also there is plenty of time before the examz commence, so I dont see any harm in joining an academy for 3-4 months.