Hello Hum Lallann Bol Rahe Hain is the story of a security guard. The film revolves around Lallann Prasad Prajapati (Rajpal Yadav), who hails from North India, an educated and well-mannered man who works in Mumbai as a security guard. He is self-sufficient, confident, and honest and believes in the 'live and let live' philosophy. He is very attached to his friends and involved in solving their problems.
He worships his work. Among Lallann's close friends and well-wishers are Ganesh (Makrand Anaspure), a Maharashtrian who drives an auto rickshaw for a living, a Gujarati lady (Ketaki Dave) who owns an STD booth, and his boss (Ravi Jhankal) whom he treats like an uncle. He is very fond of his childhood sweetheart, Saroja (Preeti Mehre), who lives in the village but is in constant touch with him on the phone.
He dreams of a secured life for himself and Saroja together and he works hard to realize this dream. But his love is one-sided.