Hi Aspirant ,

As you haven't mentioned which class you belong to , I will post the free download links for both 12th and 10th grade . For NCERT , CBSE syllabus should be covered in order to pursue the exam.

For 11th grade:

https://school.careers360.com/download/ebooks/cbse-11th-biology-syllabus-2020-21

For 12th grade( with sample question papers) :

https://school.careers360.com/download/sample-papers/cbse-12th-class-biology-solved-sample-paper-2021

For 10th grade :

https://school.careers360.com/download/ebooks/cbse-class-10-science-syllabus-2020-21

Also you can find other syllabus for various subject following the link given below : https://school.careers360.com/download/ebooks-and-sample-papers?sort=recommended

BEST OF LUCK .