Various institutes have various eligibility criteria for M.Tech. However, the most standard one that every institution follow is:

1. You have to secure alteast 60% or 6.5 CGPA on a 10 point scale with B.Tech in the relevant branch(for example for M.Tech in CSE, you either have to have a B.Tech in IT or CSE or may even be ECE). For those students who are in the final year of B.Tech, the CGPA or percentage will be calculated up to the last year
2. You MUST qualify GATE exam. IITs and NITs won’t even entertain your application if your GATE score is below the cut offset by the organizing institute.

All the very best and good luck.

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.

Hii..

M.Tech: Duration – 2 Years (4 semesters) Admission through GATE
Eligibility Criteria:

• Regular: B.E/B.Tech/B.Arch. or M.Sc (Chemistry/Life Sciences/Mathematics/Physics) or Associate Membership holders with 60% marks and with GATE Score. IIT B.Tech graduates having 8.0 and above CGPA (7.5 for SC/ST) can apply without GATE.
• Sponsored: B.E/B.Tech first class or 60% aggregate marks in all the four years or AMIE or any other Associate membership (no need for having GATE score) and Sponsored by industry/government organizations/private and public enterprises recognized by DST engaged in R&D work/engineering colleges recognized by AICTE, with two years of professional experien