How to open MPEG-2 stream (Blu-Ray) .m2ts files
Have you had trouble opening the m2ts file on your computer? What are m2ts files? We explain what they are and recommend software that we know will open them.
What is m2ts file?
An m2ts file extension is commonly used on Blu-Ray disks for the BDAV MPEG-2 transport stream. It is widely supported HD video format and playable on almost any modern media player, and is often used for official movie releases on Blu-Ray.
MPEG-2 stream (Blu-Ray) description
The m2ts file extension is associated with BDAV MPEG-2 transport stream used on Blu-Ray discs (video file format).
BDAV refers to either the transport stream format used for all Blu-ray content, or the plain format intended for home video with no interactivity.
BDAV Container format is based on the standard MPEG-2 TS (transport stream). Both Blu-ray and HD DVD use transport streams, compared to DVD's program streams, to store video, audio, and other streams. This allows multiple video programs to be stored in the same file so they can be played back simultaneously, giving a Picture In Picture effect.
BDAV disk format is the consumer oriented alternative to the BDMV disks made by professional Authoring houses for movie releases. Although early Blu-ray players were released with firmware allowing playback of non-AACS encrypted content on BDMV discs, current Blu-ray specifications will result in that feature being removed, and BDAV disks being the only unencrypted Blu-ray format supported on players.
BDAV was designed in part to provide compatibility between AVCHD digital camcorders and Blu-ray players. It's comparable to the DVD formats used for standalone DVD recorders, DVD+VR and DVD-VR because it's designed primarily for authoring simple Video/Audio content with no menus.
Suggested software to open m2ts file

VLC media player
One of the most popular multi-platfom multimeda player