One of the biggest mistakes students make during JEE Main preparation is ignoring basic concepts and directly jumping to difficult questions. Many students also follow too many books and study materials at the same time, which often creates confusion and weakens revision. Lack of consistency, irregular study schedules, and avoiding mock tests are also common mistakes that affect performance badly. Some students focus only on strong subjects and ignore weaker areas, which reduces their overall score. During revision, students often spend too much time reading theory instead of practicing questions and revising formulas regularly. Another major mistake is not analyzing mistakes made in mock tests and previous papers. Proper time management, regular revision, limited but quality study resources, and consistent practice are very important to avoid these problems and improve JEE Main preparation.