If we are speaking in terms of the process of admission, then you must have a degree certificate that is valid and has an aggregate score of 60% or above. Other than that, having backlogs during graduation will not be a problem. For admission to NITIE, it is mandatory for you to appear in your GATE/CAT examinations.
The aggregate percentage of marks of 60% is relaxed by 5% for candidates in the SC/ST/PwD category.
If you have the minimum score to meet the eligibility criteria and have a clear reason for your backlogs then you will be granted admission. Apart from genuine reasons you will also have to be making a steady progression so the decision to grant admission is not regretted later.