99.37 CAT percentile with EWS certificate and 9/9/8 academics plus 18 months branded workex is enough for IIM Calcutta shortlist because EWS candidates get roughly 5-8 percentile relaxation from General cutoffs. The OP of this thread did exactly that: 99.
37 EWS, 9/9/8 ECE from Jadavpur University, 18 months at PwC, and landed IIM BLCKISM (B, L, C, K, I, S, M) calls. IIM C at Rs 27L fees and Rs 34.23 LPA average placement is generous with EWS candidates because the applicant pool is smaller.
The critical qualifier: EWS certificate must be current (income below Rs 8L), so the OP's father earning below Rs 8 LPA qualified him. Without the EWS certificate, 99.37 General would NOT get IIM A or B calls; you'd need 99.
8+ General. For EWS candidates, the game plan is: clear 99+ overall CAT, secure EWS certificate in advance (it takes 60+ days), apply to all IIMs in the BLCKISM bracket, and prepare hard for WAT-PI because the interview stage is where workex and communication pull you through conversion. Engineering candidates with MS offers from Canadian universities (like Queen's Smith) should treat Indian IIMs as the first priority for ROI; Canadian MBA at 4x fees with uncertain visa outcomes makes IIM C a smarter bet.
Check your eligibility at collvera.