While many sites offer pirated content, several legal and safe alternatives provide a massive library of dual audio and Hindi-dubbed content. 1. MX Player
What is illegal is downloading or distributing a copyrighted movie without paying the rights holder. If a movie is in the public domain, or you have ripped it from a DVD/Blu-ray you purchased, a dual audio copy is legal.
Tips for finding good dual-audio Hindi movies legally
Tap the screen or press the options button on your remote to bring up the player controls.