Hi Shubham,
General criteria for BBA course is that a candidate should have passed 10+2 examination from recognised board, university or council with a minimum 50% marks or 45% marks respectively depending upon program / institute they are aspiring to take admissions. Almost all colleges accept NIOS student except Amity University, As you got 70% in class 12th so you will definitely get admission to BBA course.
All the best!!
Yes...you can apply for iims if they providing BBA course.
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