This is a grey area. Subtitles are copyrighted textual translations of dialogue. However, most subtitle download sites operate under "Fair Use" for educational and accessibility purposes.

Given the keyword is from 2021, many OTT subscriptions have since lapsed. The safest legal route today is to rent the film for $2-3 on YouTube or Google Play. If the platform lacks English subtitles, using an external .srt you downloaded for personal accessibility is generally tolerated.

If you want to avoid the download hassle altogether, check these platforms (availability varies by region):

Best legal path:
Watch Pyaar Impossible! (2010) on Amazon Prime Video with built-in English subtitles.
Second best: Buy/rent from YouTube or Google Play – subtitles included.
If you own a DVD/BD without subs: Download from OpenSubtitles.org.

Avoid any site promising "Pyaar Impossible 2021 subtitle download" – it’s either a nonexistent film or a dangerous file.

Would you like a sample .srt file content (first 5 minutes of the film) for educational purposes? I can provide that as text so you can see the format.