Yes, legally. Install the ZEE5 app from Google Play Store or Apple App Store. Tap the download icon next to the movie. The file will be saved in the app’s secure offline library, not in your public storage.
Which of those would you like?
As for downloading or streaming "Valimai," I must remind you that piracy is against the law and can harm the film industry. However, I can provide you with some legitimate options: valimai tamil movie upd download