Hi chetan.
Firstly in order to tell you important topics, you need to tell me your subjects.
Anyway, in cbse exams you can't predict what may come. It's always better to be on safer side. Go thoroughly through whole of your syllabus.
It will make your concepts strong for 12th standard.

Do revert me back with your subject.
If you like the answer, kindly upvote.

Goodluck.