Steps to restore FusionRetail 6 data from a backup file.

1. Go to FusionRetail6 Folder
2. Delete FusionRetail6.exe.config file
3. Now Run FusionRetail6.exe
4. Database manger Screen will open
5. Press Next
6. Server Name, Authentication and user name will automatically carried
7. user password should be blank and click Next
8. Select restore from database process mode and click on Next button
9. Enter  database name and select the file from the location and press next
10. Press Yes to “Want to restored selected database backup”

For more info : 

http://www.rancelab.com/help/fr6_setting_up_the_database.htm