The company said Jio Wi-Fi calling - which works on the largest ecosystem of handsets - will also allow users to make video calls over Wi-Fi. The service would be available for free.
The announcement comes less than a month after rival Airtel launched a similar service in Delhi-NCR.
Jio said it has been "testing this service over the past few months to provide a robust experience to every customer at launch".
Customers can use any Wi-Fi network for Jio Wi-Fi-calling. The voice and video calls will seamlessly switch over between VoLTE and Wi-Fi to provide an enhanced voice/video-calling experience, it added.
"At this juncture, when an average Jio consumer uses over 900 minutes of voice calls every month, and at a growing base of consumers, the launch of Jio Wi-Fi Calling will further enhance every Jio consumer's voice-calling experience, which is already a benchmark for the industry with India's-first all VoLTE network," Reliance Jio Director Akash Ambani said.
Jio Wi-Fi Calling will be enabled pan-India between January 7 and 16, the statement said. SR SR ANU ANU