Start your preparations for the IAO as soon as possible. Since the syllabus is very broad, six months is a decent amount of time to offer yourself for preparations. Examine previous year's papers for trends in question papers. Brush up on your problem-solving skills, including calculation, interpretation, and method. This is what is highlighted every year. Make a detailed study of the major constellations as well as the main stars in each constellation. This is a constant topic in INAO. Students who have taken the exam before will also advise you to research Astronomy-related topics using constellation software, firsthand information from Wikipedia, or relevant websites a few days before the exam.