Physics Preparation

Hi Uttam,
First of all, wishing you a very best of luck for your Class 12 board exams and for your future.
Well, coming to the question, you are asking how you should prepare Physics for your boards (As I assume). In this answer, I will try my best to give you a good way to succeed in your boards.
Physics, is, was and always will be a big subject to all Science students appearing for board exams. The main reason for this is that the topic you have to study is a bit vast, and you need a good strategy to nail it.
1. Books
As far as your Board exams are considered, the CBSE prescribes you two books (NCERT Textbook) NCERT Exemplar Textbook though the board, and we all know that these two books won't cater to all needs of all type of students, this is what CBSE has prescribed. For you board exams, you should be well enough in getting your concepts very well. In Recent years, CBSE has started to ask questions in a twisted manner, that makes the student to think twice before answer, so my best bet would be to use SL Arora book as a reference book for your boards. The book is very good in providing you in depth understanding of concepts due to its student friendly presentation.
2. How to prepare from books
Simply reading texts and your notes are not going to fetch you a centum in your boards. There needs to be a clever strategy to be made sure that you cover all the In text questions and Exercise questions that are given at the end of each chapter. Study all the graphs that are given alongside with the text portion. Be very vigilant in writing laws- Make sure that you dont alter the meaning of laws that were predefined by others, Do numerical questions sincerely. For this, NCERT Exemplar book is really going to help you out. This book has a higher level of problems which will help you to brush up your knowledge. Also, it will help you a lot, if you are an IIT aspirant. Be sincere in your studies. Never cheat yourselves that you know everything from textbook. Once you finish this, go and try solving old question paper questions. Analyze yourselves on how you perform while solving these questions. This helps you to find where you lag or where you excel.
Keep practicing.
All the best.