Hello

The information I am going to give you will not only help you for AIATS but also for NEET.

You need to focus on NCERT and NCERT alone.

Go through previous year papers ad find teh pattern as to which consepts are the most important.

Write down all the formulas and practice atleast ten questions revolving around that formula, preferably of different types

If you have any doubts then you can always use youtube for conceptclarification. Vedantu provides the best free material on their youtube channel.

Allot the time to different sections of the paper depending on how difficult you perceive them to be, you don ot have to attemt them all, youjust have to make sure that you attempt the one you are sure of.

Set a timer while solving papers, make sure your body system becomes accustomed to give exams under time pressure and try to adjust your biological clock to the time zone in which the exam will be conducted (AIATS is usually conducted in the  afternoon).