Surprisingly, YouTube is the most extensive legal source. Many production houses have official channels where they upload remastered versions of old Kannada movies for free.
Using unauthorized sites like torrents or Telegram channels to download movies may seem convenient, but it carries significant risks: Download Old Kannada Movies
If you are looking for a or a particular era (e.g., 60s musicals vs. 90s action), let me know so I can help you find the right legal source! Top Rated Kannada Movies - IMDb Surprisingly, YouTube is the most extensive legal source