i m presently studying in 12th . ithink i hv wasted ny entire 11th and doesn't knew even the basic concepts. would it be too late too start studying seriously? i know that i hv the capability but i neglected my studies .what should i do now?from where should i start? please guide me!

Yes , thats a big mistake that you have done .... the time of 11th and 12th standard is very important for making concepts if you are preparing for IIT...  but its not too late .. do lot of hard work and forget everything for one year start studying .. you need to cover the sllybus of 11th std. You can do self study and also you can take coachings so that you go side by side for IIT Preparation.. You need to put double efforts ..

Wish u a very good luck !!