There are several legal ways to watch The Passion of Christ in Tamil, including:

Mel Gibson's 2004 film, "The Passion of the Christ," is a cinematic depiction of the final 12 hours of Jesus Christ's life. The movie was a critical and commercial success worldwide, grossing over $614 million at the box office. However, its availability for download in Tamil, a popular language in southern India, has sparked controversy and debate.

: The film was originally released with dialogue in Aramaic, Hebrew, and Latin with English subtitles to maintain historical immersion. Religious & Tamil Language Resources

If you specifically need a movie with a Tamil audio track, the following are widely available: