After dropping a year for preparation of iit-jee,one has to joint a coaching institute or do self study?

See it all depends on your capacity. if u have enough self control and u feel that u can study on ur own then do self study. bt if the concepts are not clear to u then better go for coaching. one thing i would like to tell u from my personal experience. if ur aim is clear only JEE MAINS then study

I agree with Shweta at some points but will suggest, you go for a coaching class as it provides a competitive environment and proper study pattern. Also, it will be more helpful if you go for Catalyser or someone similar.