Got 3: Duet Mastercard, SaveMax Visa and ShopRite RuPay. All shared limit, all LTF. But RBL Play declined as 4th card. Reason not given except internal policy. Will complain to RBI soon to find out exact reason. Had applied after 3 months which is their cooldown period.
Since people also have combination of RBL Bajaj, Duet and Play, so 3 cobranded are allowed 🙂
Also, another person I know has RBL World Safari, Duet, Patanjali and ShopRite (2 core, 2 cobranded)