Officially Reliance Jio Sim is supported for Reliance Lyf and some Samsung Smartphones, but thanks to a bug which helps other 4G smartphone user to get free Reliance Jio Sim card and enjoy the benefits completely.
There's a good news for OnePlus users i.e OnePlus 2, OnePlus One and OnePlus X will be getting VoLTE support soon through a software update.
A OnePlus team member replied to a user question about VoLTE support on older OnePlus devices, Here's what she replied-
We are working with Reliance Jio right now on VoLTE support. Will update you all once we have a more concrete timeline worked out
Seems that OnePlus is tying up with Reliance Jio and users will be soon able to enjoy Reliance Jio's benefits.
via - techpp | source - oneplus