Use APKPure App
Get LTE to VoLTE Convert old version APK for Android
provide LTE Support
LTE to VoLTE Convert will check that your device support VoLTE.
VoLTE support is necessary on your smartphone to make and receive calls on the Jio network. LTE to VoLTE Converter check the LTE support as well as VoLTE supports.
VoLTE is required for jio join network.if you do not have volte support then you can download Jio4GVoice or MyJio.
Disclaimer:
This App doesn't have any relationship with the Reliance Jio.