My Volt
tested MTS and RIM . Voice and SMS in both work. DATA works in RIM . Haven't tested in MTS . Did not add the apn in NV mode but added the APN through APN backup Restore even when ADD APN tab is not visible in any menu
Check pics . Even shows network name in locked screen
Exactly what we did in G2 for changing APN using Apn restore app . Made a new RCOM APN in G2 as i had G2 . Any mobile should work . In new APN here on RIM people had said to use MCC and MNC as 404 and 00 due to which the APN was never saving .
So I used MCC and MNC as 405 and 51 . Saved the APN and shifted the APN to Volt .
Restored the APN using the app and it worked without any tinkering
You will have to shift the Apn Backup restore app to Priv App in System
And my ro.build.prop.country was spr . I had changed to spr as thought add APN tab might come in spr.
DATA in RUIM only works in spr and not with SPR in capital which is default . You will have to add 0 bedore every number to call or Android process system FC will come .
i did not face any issue with calls in spr/SPR
Uploaded the Reliance APN which I used . It also has 2 Airtel APN , IP4 only and IP4/6 . Delete them if you don't want them
Name of Reliance APN is "apn-RIM ip4"
EDIT UPDATED
ApnBackupRestore.zip