how to do it?...not much tym left for jee but im aiming for bitsat...plz advice..thanks

for organic chemistry questions, mechanism is the most important. if you know mechanism of a reaction, you will very easily solve the reaction. you should also remember all the name reactions.
for inorganic chemistry, formulas are important. you must try to solve maximum number of examples to get used to the solving questions quickly. and theory you will have to read atleast twice so that you can remember it well.
good luck