elected from the Sankarankoil constituency after winning the 2012 by-election

There may be a confusion with other Tamil actresses named Muthuselvi (a common name in the region), but the specific individual who served as the Sankarankovil MLA has no recorded career in the film industry. Emphatic win for AIADMK in Sankarankoil - The Hindu

) party and served as a Member of the Legislative Assembly (MLA) for the Sankarankoil

It's possible you might be referring to:

Muthuselvi does not appear in commercial films; however, her "filmography" consists of widely viewed political reels and campaign videos on social media platforms like Campaign Reels

: Clips showing her celebrations and addresses to the public after securing her seat.