One of my friends studied at NITIE Mumbai. According to him, it offers five different programs including an interdisciplinary Fellow program and a 1-year PGPEX program. The other three programs are –
PGSIM and PGDSM consider CAT scores for admission. The process of admission for all three courses remains the same.
The PGDIM course usually commands a percentile of more than 97 in CAT to sit for the GD/PI and then your overall score will determine your admission. For PGDIE, a score upwards of 750 in GATE is required for admission.
As far as toughness goes, scoring well in CAT and GATE, which are themselves pretty difficult exams, is the most important parameter.