Hey Farheen,

NCERT Exempler is considered more important. As it has fewer questions. And the onee that are generally asked in CBSE. I would recommend you Solve R.D Sharma for maths. Just solve the CBSE and NCERT tagged questions in R.D Sharma you will score great. Many questions are exactly same as the book.

If you are a JEE aspirants check out this

engineering.careers360.com/articles/careers360-talent-search-exam-ctse-2019/amp

Best of luck