Step 1. Go back into Internet Recovery>Disk Utility> highlight your working volume ("Macintosh HD", etc) and click erase. Choose macOS Extended Journaled and keep the default volume name "Macintosh HD" or change it as desired.
Step 2. Reboot your Mac and choose one of the following keystroke commands depending up which OS version you want to install (I'd recommend the last one, Internet Recovery as it will likely up date your EFI and recovery partition which might have been modified or corrupted):
Reinstall the latest macOS that was installed on your Mac from Mac Utilities "Reinstall macOS", without upgrading to a later version.1
Upgrade to the latest macOS that is compatible with your Mac.2
Requires macOS Sierra 10.12.4
or later Reinstall the macOS that came with your Mac, or the version closest to it that is still available.
Step 3. If Internet Recovery was successful update your operating system , then upgrade to Sierra by downloading a copy through the App Store unless you have incompatible apps, and lastly, bring your data back over.
If any step fails please provide as much detail as you can with error messages, etc and hopefully one of us can advise.
Here's a helpful link: