Kotak Mahindra Bank's net interest margin is likely to swell after the Reserve Bank of India (RBI) lifted its restrictions on the private lender that barred it from issuing fresh credit cards and onboarding new customers through digital mode, brokerages said on Thursday.The bank's net interest margin (NIM) has seen a decline of over 35 basis points (bps) since the restrictions were imposed by the regulator in April 2024.