frankly speaking make what u are good at more strong .eg: my friend who got into iit was excellent at physics and did physics all the day(90% of his prep time).he got 138 in physics itself.his total was 247 in jee and now he is doing wat he wanted i.e. civil at iit -b.so as he says:" iit mein koi ek subj phood diya matlab tera clear ho gaya"

if ur chem is weak,atleast try to be perfect at phyisical chem as it is more of math and logic.org chem problems should be practiced.leave inorg if u dont like (coz howmuchever u do its insufficient and its better to make ur org and physical chem stornger than doing thiis).