Hi

It differs from person to person while personally i say is better go for coaching because in couching you'll get wider and easier ways to crack exam but self study is quite hard

Hope this helps

Hello, 

There is common misconception that without coaching You can not crack CAT, But it is Not the fact Coaching just can guide You regarding Your preparation and If You can manage Your study syllabus By strong planning then you can avoid Joining coaching Institutes, But having study material is Good thing, Apart from going for a study material from Coaching You can buy some Good Books they may be helpful In making You qualify the exam, So Just remove that thought that without coaching it won't be possible.