Mumbai,8/1: Telecom giant Reliance Jio has launched its free wifi calling. This includes free voice and video calling over WiFi network. Previously, Airtel also launched a similar service but only a few selected devices of Apple. Xiaomi, Samsung and Oneplus. But Jio Wifi calling will be supported in more than 150 devices. But to enjoy this service, the Jio users must have an active tariff plan. Mobile users can make video and voice calls when connected to a Wifi network even when they have no network.