My aim is to study in the best B-School of India but my parents are not able to afford fees for colleges like IIM? What should I do?

You must write MBA entrance exams. Try to score higher scores. There are many good B-Schools with low fees. You must target for colleges like Faculty of Management Studies, Delhi JBIMS-Mumbai NITIE-Mumbai TATA Institute of Social Sciences -Mumbai IIT-Delhi/Roorkee/Kharagpur/BHU K. J. Somaiya Insti