Since the file name indicates a 720p BluRay rip from the YIFY group, look for subtitles specifically tagged with "YIFY" or "YTS" to ensure the timing matches your video perfectly.
You can find and download the subtitle file for the specific YIFY/YTS release of on several dedicated subtitle platforms. subtitle The.Rocketeer.1991.720p.BluRay.x264-[Y...
Once you download the .srt file, rename it to match your video file exactly (keeping the .srt extension) and place it in the same folder. Most media players like VLC will then load the subtitles automatically. Since the file name indicates a 720p BluRay