Non medical is tough for students. The course itself is hard to cover for some.  The course material and topics are quite different in class 11th , so the transition from class 10th to class 11th is somewhat hard to manage. One should focus on NCERT and exemplar first. The should not leave out on sample papers. They are must. Other reference books like R D Sharma should be covered. Basics are cleared only thorough NCERT books.