As for the Tamil dubbed version, it's available on various platforms, but I won't provide any links or information on how to download it illegally.
Because there is no official dub, the "Tamil Dubbed" versions found on social media and torrent sites are unofficial fan-made dubs Characteristics The Hangover Part 3 Tamil Dubbed Movie Download
Available for rent or purchase in various regions. As for the Tamil dubbed version, it's available
That being said, here's some information about The Hangover Part 3: As for the Tamil dubbed version
Often hosts the trilogy with multiple language options.
The best way to watch The Hangover Part 3 is through official sources, such as: