Greetings!

Well, there are no such chapters in particular!

Yes you heard that right, now I won't say all of them are completely useless and you are not going to need any thing from them, or that they are not important.

But the thing is that in college you will be taught most of those important chapters again, so you don't really need to worry about it right now, having knowledge of CSE in college does gives you an edge, however that edge is not enough to compensate difference between an NIT and a local college, therefore my recommendation would be to focus on JEE for now.

With that being said, let's see which are the most important topics from CSE prospective that are being taught in 11th and 12th, First topic that I would like to mention is, Logic gates and truth tables, believe me in 1 year of my college life I have been taught logic gates by 4 different teachers for 4 different subjects. Yes they are that important, they form basis of many subjects.

The second topic I would like to mention is your mathematical logic, you are definitely going to need to learn that if you join any CSE related course.

Then next topic would be your Sets, and Relation and Functions, both of them are useful in various subjects ranging from Theory Of Computation, to solving Data Structure problems.

The last topic I would like to mention is Probability and P&C, while solving medium to tough problems in competitive coding, many times you will observe that you are going to need the concepts taught in these chapters...

But that is pretty much it according to me, rest everything is either taught from the very basics in college or is not needed.

~Sach Thadani