hello aspirant,

for ipe 12th garde for pcm you need to refer to ncert of all subjects without fail because it is the base for all subjects and all other concepts related to the basic conceptrs will be extension or deeper level of ncert topics like for jeemain and advance.you can refer to the following link for pdfs of ncerts:

https://school.careers360.com/ncert/ncert-books-for-class-12

hope this helps,

thankyou.