Reliance Jio services will be open to everyone from Monday, and you can get a SIM and enjoy free usage until December 31, until the plans kick in from next year. The entire Reliance Jio network runs on data, which means even voice calls are data-powered.
What this means for you is that you will need a VoLTE capable phone to make calls on the Jio network. You can still use 4G phones that support Jio’s LTE band, but you will not be able to make calls unless your phone supports VoLTE. Reliance Jio is offering app-based workarounds to let you call any number on such cases, but to enjoy the true Jio experience, you need to have a VoLTE use to make the most of the network.