Hey there, @shfaque.
I see that your iPhone 6 is no longer showing the correct time. Great job on the troubleshooting you've already applied and I'm happy to help.
How to back up your iPhone, iPad, and iPod touch -- Since you've already reset the network settings and all settings, please be certain you have a fresh backup of your iPhone to keep your personal information safe.
Restore your iPhone, iPad or iPod touch to factory settings -- This process will completely wipe the iPhone to allow a fresh copy of the iOS software to be installed. The first time through, select "Set up as a new iPhone". Once your iPhone has returned to the Home screen, if everything is working as it should, use the "restore your device from a backup" link located in the "Get Help" section.
If your iPhone still isn't showing the correct time, let me know.