There is only one file type that uses the .N3R extension:
Panasonic Security System Video File
An N3R file is video created by a Panasonic security system, which includes the WV-ASM200, WV-ASE201, WV-ASE202, WV-ASE203, and WV-ASE204 versions. It contains video recorded by Panasonic security cameras and downloaded using the security system management software.
Panasonic security systems come with management software to control the system. The included program is called "Operation Software" and requires your username and password in order to log in. The program allows you to control assigned cameras. You can save images to the JPEG format, print images, and choose camera views.
You can also download video from the security cameras using the "Operation Software" program. The video is saved in the proprietary N3R format, which can be played by the "ND_Viewer" program that comes with the security system. This utility also allows you to convert the N3R video to the .MP4 video format, which can be played back by a larger amount of video players.
Updated: March 4, 2017