Mummy 3 Tamilyogi ((free))

If you are specifically looking for the Tamil version, check local digital retailers or cable "on-demand" services which frequently carry the dubbed trilogies. The Mummy: Tomb of the Dragon Emperor (2008) - IMDb

If your search for is specifically for the Tamil dubbed version, the legal options are fewer but existent. Check:

The Mummy 3 is a flawed but fun blockbuster. Watch it the right way. Your computer’s health and your conscience will thank you.

Compare the used in the film to real history List where to stream the movie legally in your region

Instead of typing "Mummy 3 Tamilyogi" into a search bar—only to be bombarded with pop-up ads, malware risks, and broken links—spend a few rupees to rent the film legally. Not only will you get crystal-clear 1080p or 4K video with proper 5.1 surround sound (compared to the tinny, watermark-ridden audio on Tamilyogi), but you will also sleep better knowing you haven’t contributed to digital theft.