Since there is no single, universally famous book or play solely titled in mainstream Bengali literature, it is highly likely you are referring to the popular YouTube web series/drama titled "Polash" (often categorized under Probashi or expatriate content), or the general genre of Probashi (expatriate) Natoks that feature characters named Polash.
Probashi Natok: The Cultural Lifeline of the Bangladeshi Diaspora probashi natok polash
