You can apply to NITIE if you are an engineer. There are two ways in which you can get into NITIE. Either through the CAT exam or through the GATE exam.
You can apply for PGDIM or PGDISEM if you are applying through the CAT exam. Otherwise, you can apply for PGDIE, PGDPM, or PGDMM course if are applying through GATE exam.
After clearing the criteria in exams you have to face PI and GD rounds to get into NITIE. You will get a call if you are shortlisted in the final merit list after the GD-PI round. You will get the detailed admission procedure on the official website.