Hello there.
By completing NCERT if you mean you have read every line of it, solved all the examples and all the exercise questions then great, you have successfully completed the first stage of your preparation. But, this wouldn't be enough to score 100+ in the examinations. By the details of your question, I'm assuming you are preparing for writing the NEET examinations.
See, even though, NCERT is a big part of the preparation but it is surely not enough. You have to solve more questions, you have to refer more books to have a very solid grip of the subject matter.
I'd suggest you to solve the following books, you'll find direct questions in the exam from these particular set of books:
1. N. Awasthy, Vibrant Academy - Physical Chemistry. This book is written for JEE mains but it is perfect for NEET candidates who are aiming to score high in the exams.
2. VK Agarwal, Vibrant Academy - Inorganic chemistry. This is for JEE Mains too but is more than enough for practicing questions for NEET.
3. Arihant Publication Organic Chemistry for NEET, AIIMS
After completing the above mentioned books do solve MTG Chapter wise previous year questions.
With this approach, you'll surely get 100+ in the chemistry section.
Hope this helps.
All the best.
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