All the topics are important but Here are some topics which is asked frequently in the exam.

Biology: Ecology, Biotechnology, Anatomy of plants, Cell, Microbes in human welfare, Plant Physiology, Genetics.

Chemistry: Major portion is from organic chemistry, from inorganic questions are directly asked from the ncert textbooks. Physical chemistry is less.

Physics: Heat and Thermodynamics, Optics, Semiconductors, Current electricity, Mechanics.

Good Luck!