Believe it or not, some translation enthusiasts host subtitle files on GitHub. Search for "chathuram english srt" on GitHub. These are often fan-translated but can be surprisingly accurate.
Available via their website or the Google Play Store app.
Click download. The file will be a .zip or .srt file. Extract it if necessary. Save it in the as your movie file, and name it exactly the same (e.g., Chathuram.2021.mkv and Chathuram.2021.srt ). VLC Player will auto-load it.
If you already have a legal digital copy of the movie and just need the subtitle file, several dedicated communities provide them. Look for