Several major streaming services offer ad-supported "free" tiers that allow you to watch full-length Tamil movies with subtitles.
MX Player (Free) Why watch: This is art cinema disguised as commercial fare. Vijay Sethupathi plays a trans woman reuniting with her son. The subtitles here are crucial to understand the dark humor and philosophical rants.
By following these tips and recommendations, you can enjoy and experience the best of Tamil cinema.