Most HSC candidates lose marks not because they never learned a topic, but because they never practised recalling it under pressure.
Weeks 1-3: rebuild the base
Cover the highest-weight chapters first. End each day with ten questions from memory, closed book.
Weeks 4-6: past papers only
One full paper every alternate day, strictly timed, marked the same evening with a written error log.
Weeks 7-8: error-log revision
Revise only what you got wrong. This single habit is worth more than a fourth read of the textbook.