Studios often try to find Tamil voice actors whose tone matches the original English stars (e.g., the Tamil voice for Iron Man or Thor).

Because Tamil often requires more syllables to convey the same meaning as English, you might notice actors' mouths moving long after the Tamil dialogue has finished.

What of movie are you most interested in watching in Tamil?

If you're looking for a review of the English-to-Tamil dubbing quality in movies, the consensus is that while the technical standards have improved, the experience often depends on the genre and the specific studio handling the dub. The Good: High-Stakes Action & Animation