As your 12th percentage is below 60%, you will face difficulty in getting a shortlist. NITIE selection criteria assign certain weightage to 10th and 12th scores. So, even if you get shortlisted for the GD/PI round, your 12th percentage will bring down your overall score. A person with similar GD-PI performance and a higher 12th percentage is more likely to get preference for admission.
During the Summer internship shortlist, most recruiters usually give weightage to the 12th score. There are recruiters who don’t assign weightage to 10th and 12th scores but these are fewer in number.
A few of my friends graduated from NITIE so I know a little bit about the admission process there. It’s unlikely to get admission into the PGDIE course of NITIE with such an academic score.
The minimum eligibility criteria for admission in NITIE is 60 percent in 10th and 12th classes for the general category students, 55 percent for the SC, ST, and PwD category candidates.
Since you have 52% in 12th, which fails to clear the minimum percentage eligibility criteria of NITIE Mumbai.