If the Tamil dub is not available on OTT, it is likely because the producers didn't see enough paid demand for it. When you pirate it, you prove their point that Tamil audiences won't pay for it, ensuring future films skip the Tamil dub altogether. It is a vicious cycle.
If you want to watch the movie in Hindi (with Tamil subtitles if needed), here are safe, legal options: Student Of The Year 2 Tamil Dubbed Isaidub
