Hi Aspirant

Since you are taking a year drop the most important thing for you is revisit the concepts that you were weak at in the first attempt.

Moreover another important thing is to practice a lot by taking many mock tests since they help you evaluate the mistakes that you make under pressure during an examination.

As long as you kept the necessary material for this and teachers who can help you clear your doubts it is alright to join any coaching institute.

Hope this helps. All the Best.