TamilRockers is arguably the most famous name in South Indian piracy. While the original domain is long gone (seized by Hollywood or Indian cyber cells), countless mirror sites and proxy domains use the "TamilRockers" brand. They release new Tamil movies in HD-MKV format within hours of theatrical release.
They do not host the files themselves. They use third-party file hosting services like Google Drive, Telegram channels, or torrent indexes. When you click "Download MKV," you are often being redirected through 5-6 ad-filled pages before you see an actual link. Tamil Mkv Movies Download Sites