Yes, set this settings. You need to add two separate access points for jio sim.
Under access points delete all apns present and add these two new apns:
1)
Name- ims
APN- ims
APN type- ims
APN protocol- IPv4/v6 APN roaming protocol- IPv4/v6
Save these settings ( this is important for calls/sms, it probably won't show up after saving but don't worry, it'll be there for rescue

)
2)
Name- Jio Internet
APN- jionet
APN type- default
APN protocol- IPv4/v6 APN roaming protocol- IPv4/v6
Do not change other values. Save this profile and select it.
Reboot once. Your volte should work flawlessly in roaming.
Hope it helps.