A single .mkv file can hold multiple video tracks, multiple audio tracks (e.g., different languages), and multiple subtitle streams.

If the file is not supported by a device, it can be "remuxed" (copied without re-encoding) into an MP4 container using tools like Xmedia Recode or Avidemux .

To give you more specific details about the content, such as , audio languages , or subtitles , could you share: What is the approximate file size ?