According, to JEE Main 2017 analysis in organic chemistry  Alkyl Hallide, Alcohol & Ether (Reaction Mechanism) holds 13.33% weightage other topic don't have much weightage. So, make sure you understand this topic well.

To clear your concepts you can take help of NCERT books. After, completing NCERT books you can go for OP tandon and Arihant book.

You can take help of your teachers to clear your doubts or you ca join any study group.

Solve previous year problems to understand the type of questions asked in the exam and solve MCQs related to them for your practice.

All the best for your preparation and exam!!