"Sadda Adda" is a Hindi/Urdu phrase meaning "our hangout/place" or "our spot" (sadda = our, adda = hangout). "Filmyzilla" is the name of well-known websites that illegally distribute movies, TV shows, and other copyrighted content. Put together, "Sadda Adda Filmyzilla" appears to reference a hangout or collection associated with or mimicking sites that host pirated films.
While the "Sadda Adda Filmyzilla" search is common, using such piracy sites carries significant legal and security risks. sadda adda filmyzilla