Dubbed movies often change jokes or cultural references to fit the new language. Having an original English or Tamil subtitle track lets the viewer see what was actually said.

You can watch the full Hindi dubbed version of the film here to see how these features might be applied:

Since this is a Hindi-dubbed version of a South Indian film, viewers often face two issues: losing the original cultural nuances or missing context from the background text (signs, letters, etc.) shown in the original language.