VLC subtitles not working in render/cast

I'm unfamiliar with adding subtitles to movie files. I have been able to use subtitles in movie files that had the subs embedded in them, whether I watch them on my laptop or cast them to my TV. Tonight after several attempts, including updating VLC player, changing settings in the expanded preferences, I was able to load a .srt file and get them to work on my Mac OS laptop but when I cast to my Chromecast on my TV they were not present. I tried several times to restart the program but alas never worked when cast to my TV. Please help.