Yes ...you can do ..being a average student as u...i dropped a year and started preparing by joining coaching....I faced some problems in starting and gradually it get closed bcoz gradually i started to feel science ....u can do this but one and only one method is that dont cramp anything ..its a most important method to get in IIT ...
In the starting of my coaching i cramped many things..but slowly i realise that cramp is not the worth to join iit ...
You hve to do feel the subjects ....I know that some chapters like inorganic in chemistry and many other chapters that u hve to memorise ....my suggestion is that leave that chapters ...yaa its right leave that ....only 45% syllabus must to get into an iit with good branch....
So my suggestion is that feel the subjects espacially physics ..and do maths problems as much as u can do...
Dont take stress and anything just focus on studies with fun ...
Last thing dont make the time table its my experience...do only think about present day and next another day ..thats it takes u out from stress ...Yaa a one famous line is ..Best strategy is no strategy ...
So best of luck if u drop ...dont get influence in coaching if u join..yaa they take more efforts on toppers...
So if u join ur choice ..or another take a unacadmy lectures and take from youtube..
Ok ..wish for ur great future