For JEE Advanced 2025 preparation, focus on some relatively easier chapters to build your confidence. In Physics, you can start with Optics, Fluid Mechanics, and Thermodynamics, as they are more manageable compared to other topics. In Chemistry, Organic Chemistry, especially reactions and functional groups, is easier to grasp. You can also focus on Basic Inorganic Chemistry and Surface Chemistry. In Mathematics, Coordinate Geometry, Trigonometry, and Integral Calculus are usually less complex and will help strengthen your basics. Once you’re comfortable, gradually move to tougher chapters while practicing and revising regularly.