After lots of research i find a working method for fixing imei 0 issue.
I only checked on indian variant. If your varriant also work then let me know in the comments
Qpst - https://www.qpstflash.com/
Lgup crossflash thanks to @Inerent - https://forum.xda-developers.com/lg...ash-oreo-pie-firmwares-lg-g7-g7-t3915303/amp/
Efs professional tools- https://forum.xda-developers.com/attachment.php?attachmentid=3087596
Lg710vm firmware- https://lg-firmwares.com/downloads-file/21622/G710VM20e_03_1205
Download all the above files
1.a Open qfil. Select firehouse and go to configuration
And select ufs and select ok
1.b open tool-partition manager and erase modemst1 modemst2 and fsg
2. crossflash to lg g710vm firmware.
3. Enable port check using code ##7764726710 after 000000
4.a open efs professional tool- Qualcomm nv tools
4.b connect and go to secure manager here write your imei
4.c reboot your device and check now your imei using *#06#
5a. Open network setting go to network mode and select global
5b. Reboot boom! You can use network now.
Here is video tutorial -
Special thanks to @netookska05 @sumit0nine