Coaching classes use different methods to those utilized in the classroom. This means alternative approaches to learning that could be more suitable to your child are made available. Various teaching methods can be beneficial to different children; if your child is being exposed to two kinds, there is a very good chance one will be effective for them.
Children receive more individual tuition at coaching classes, meaning teaching is catered to their abilities more directly. If your child does not receive one-on-one tuition in coaching classes, they will at the very least be in very small classes. They will have a learning plan tailored to their needs, allowing them to succeed at an increased pace.
Coaching classes can be provided specifically for certain entrance exams. This gives your child a head start in the admissions process, placing them above candidates that have not had coaching classes. Therefore they are more likely to gain a place.
On the other hand, coaching classes do have a number of disadvantages:
They are, in most cases, unsubsidized and very expensive.
They can pile pressure onto your child, who is likely to already feel nervous about upcoming exams. Your child may worry that even after the coaching classes they won't pass, which will leave them feeling stupid and unmotivated to learn.
Coaching classes could artificially boost your child's performance. This may not be in their best interest as they could be placed in a school not suited to their abilities.