Hello dear..you didn't mentioned from where you want to pursue your course or in which College you are interested in that case I can give you roungh idea. Firstly there is no shortcuts to crack any exam only your hard work can make it happen. Secondly there is no accurate syllabus to crack your exam thoroughly study your +2 books , it will help you a lot.

For deep and better understanding of your subject you can also consider NCERT books of class 11th and 12th. Keep yourself update with the changes going around. You can read Economics books from online library. And can also go through journals related to Economics.

Hope it helps

Good Luck