Fitst I will suggest you let him join any coaching classes.Because as he starts preapearing for IIT JEE then he will face a tough comptition.
coaching classes can guide in a better way.
he is class 9th so now let him concentrate in his study
from 11th standard is the best time to start prepration for IIT JEE.beause now IIT JEE has limited number of attempt ,one can attemp only two time one with 12th and one just after the 12th.
and regarding the self study.certainly one can do self study.but if he will do self study then he will miss lot of concept which are not well explained in the books.and it will affect on his final result.
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