Hi there. 

Taking coachings completely depends upon the capacity of the student. 

If a student is capable enough for cracking the exam with high motivation, strong determination, undying passion and the zeal to go on even after consecutive failures, along with highly efficient study material then by all means there's no need of joining coaching. 

But if a student feels the absence of any of the above then they should try taking coaching once. 

Coachings not only keep you motivated, but with well structured study materials, experienced faculty and many mock tests, your chances of cracking the exam go very high. 

You should refer to Universal Guide for CLAT/LLB for self study purposes. Trust me, this book is enough to crack the exam. 

Wishing you luck!