This is one of the problems many students face as they don't give importance to class 11 chapters. We are often told just to pass. But one thing to understand, that you must read all the topics of 11 to understand the topics of 12. They are interrelated. In this one year time, you must complete the chapters of 11 first, then move on to the chapters 12. Class 11 syllabus is the building block.

Some of the important chapters of Class 11 Physics that you must cover-
Heat and thermodynamics, waves, laws of motion, Gravitation, Simple harmonic motion, Work, power Energy, Fluid dynamics.

Chemistry-
Mole concept, thermodynamics, Chemical bonding, Redox, periodic elements, Atomic structure, equilibrium.

Maths-
Quadratic equations, limits, Derivatives, Permutation and Combination, Sets, relation and function, Ellipse, Parabola, Hyperbola, probability.