Online course of Aakash Institute does provide you with adequate study material and lectures, but I would still prefer online classes over it.
Obviously, one can concentrate better and be more sincere in offline classes. The doubt solving, I think is more effective offline. However, that is debatable.
I think offline classes are best when your residence is close to the center and shifting to a PG or hostel isn't the most convenient solution.
Online classes can provide you mobility in terms of where you are taking classes from. If there isn't a center in your area, I suggest go with online but if there is one, offline is the best.