The word "exclusive" in is a pure fabrication. Piracy sites do not have "exclusives." They scrape content from legal CDs, OTT screeners (recorded illegally), or other pirate sites. There is no "Director's Cut" or "Special Edition" hidden on Filmyzilla that isn't available on legal platforms.
The first film adaptation of Byomkesh Bakshy, "Satyanweshi," was released in 1943, starring Ashok Kumar as the titular character. Since then, numerous films, TV shows, and web series have been produced, featuring various actors as Byomkesh, including the likes of Uttam Kumar, Soumitra Chatterjee, and Prosenjit Chatterjee. detective byomkesh bakshy filmyzilla exclusive