Since you have a specific release ( 7.Days.In.Hell.2015.1080p.WEBRip.x264 ), you should look for .srt files that match this exact filename to ensure the timing is synced correctly. Reliable community sites for these files include:
: Open the video in VLC, then drag the .srt file directly onto the player window. Permanent Embedding (Hardcoding): subtitle 7.Days.In.Hell.2015.1080p.WEBRip.x264....
You can find the official version with built-in subtitles on HBO (Max) or Apple TV . Since you have a specific release ( 7