That is really tough as no one knows exactly which topic will be given more weightage. See 80% of the weightage is given to class 12 topics, 20 % to class 11. this makes it easier so first step is to concentrate on class 12 topics. Second check some of the past year question papers. they will give you a good idea of which topics have been covered more. My advice is that all topics are important. If you miss one also then youo stand a chance of losing a question. Click here to read more.