Idea Cellular has emerged as the biggest gainer of the mobile number portability scheme, having gained 17 million net port-ins until January-end 2016, broker firm Kotak Institutional Equities said on Wednesday. Vodafone (11.1 million) and Airtel (7.3 million) were the other two gainers. Reliance Communications, with net loss of 10.8 million, was the biggest loser, followed by Aircel (6.6 million).