Check out fan forums like (Note: We do not endorse piracy; this is for informational awareness only) or Reddit r/Chennai . Fan groups sometimes create "dubbing parodies." These are 10–20 minute clips, not the full movie. Search for "Shrek 2 Tamil fan parody."
Websites offering "I Shrek 2 Tamil dubbed link" for free rarely have the movie. Instead, they have: i+shrek+2+tamil+dubbed+link