if the stream comes with subtitle you can find them by using VLC, then once movie starts click middle button or pause button, then scroll left, then click on message bubble and a submenu will pop up, then scroll down and right, and there is your list of subtitle, highlight that one you want, done. If stream does not have subtitle, it will be empty. To download subtitles is a bit of work, maybe someone else will chime in

In the more decent apps you can simply select the built-in subs; if not available in your language there should be an option to search for them on several sub sites from within the app.

Do you mean that you want to add subtitles to the online streaming video?

Adding subtitles to any particular model of TV is quite tough due to format technicalities and other various issues involved. Actually, only the publisher of the movie can directly add subtitles to the movie.

Instead you should look forward to add subtitles through your laptop. If you are interested in it, you can check this article about how to add subtitles to a movie .