Firstly, do not make the mistake of surronding yourself with too many books. Stick to a certain set and only buy more books when you are done with the ones you have. For Physics, HC Verma has been the standard book for many years and still remains the undisputed king. Go for the Arihant book series for mathematics, especially calculus. For Chemistry, refer to P Bahadur for physical chemistry, NCERT textbooks for inorganic and OP Tandon for Organic. If you don't have much time and haven't given much time to preparation, forget it. Focus on JEE Mains by consulting NCERT.