For non-commercial fan art, most production houses tolerate derivative works, but always credit the original designers.
The original Vishwaroopam poster uses:
Here’s a feature concept for a — a custom typeface inspired by the cosmic, multi-armed, all-encompassing visual form of Lord Shiva as Vishwaroopam (from Hindu philosophy and cinema, especially Vishwaroopam 2013 film). Vishwaroopam Font Style