Possibly, if Lionsgate (the distributor) sees enough legal demand. You can request it by filling out suggestion forms on Amazon Prime Video or Disney+ Hotstar.
Here are some legitimate sources where you can stream or download "Now You See Me" with a Tamil dub: Now You See Me Hollywood Movie Tamil Dubbed Download
If you can't find the movie on official streaming platforms, you can try searching on websites that specialize in Tamil dubbed movies: Possibly, if Lionsgate (the distributor) sees enough legal