Balkhrushna can you please tell me if you got admission in any NiT then as i am in the same situation now. 

As far as I can recall, it is not more than 60% or CGPA 6 in any IIT. IIT delhi enforces 60% for general and 55% for obc students. Most of the IITs just require a pass.
Number of past backlogs doesn't matter but you must make sure that before taking admissions, you must not have any pending backlogs. Before planning to repear go to the cut off marks well and investigate first before taking any action. In my  books you r eligible for mtech easily.