There is only one file type that uses the .NFC extension:
Nokia Phone Backup Copy File
An NFC file is a backup file created by Nokia PC Suite, a Nokia phone synchronization and management application. It stores a backup of the phone's data, which includes system and user data. NFC files are used for restoring phone states, as well as transferring data to another phone.
NFC files are actually created by the Nokia Content Copier program, which is part of the Nokia PC Suite software. Nokia Content Copier is sometimes also referred to as "Backup and Restore."
NOTE: Nokia phone backup files also use the .NBU and .NFB extensions.
Updated: November 11, 2017