Purbarag follows the journey of Indranath, a young man deeply influenced by his early childhood experiences. Orphaned at a young age, Indranath finds solace and guidance from his teacher, Jatileswar Chatterjee, and his family. After completing his education, Indranath returns to his hometown and encounters both familiar faces and new challenges. The film explores themes of loss, love, friendship, and the search for meaning in life. Indranath's experiences reflect the societal changes and cultural shifts of the time. Through his interactions with various characters, he grapples with the complexities of human nature and the importance of personal values.

The story revolves around the last life crisis of Jamini Mohan and his wife. After his retirement, Jamini Mohan and his wife Santoshini continued to be despised in the family of their earning sons. At this time, Gobinda, an orphan of a distant relative, became their mental hope. After facing various humiliations from their blood relationship Jamini Mohan died and as the mother of three sons, Santoshini became a burden to this family. Eventually, Gobinda became Santoshini's absolute refuge.

A person vows to eradicate the rumors of a haunted house.