Nayyi Navelli revolves around Mohini (Yami Gautam Dhar), a successful company head who marries Raja Awasthi (Addinath M. Kothare) from Meerut and moves into his large joint family. With her charming personality, Mohini quickly wins over Raja’s family, including his parents, S. K. Awasthi (Suneel Sinha) and Asha (Sunita Rajwar), his brother Bantu (Anurag Thakur), grandmother (Sushmita Mukherjee), Pinky Bua (Mita Vasisht), Pannu Chacha (Prateek Pachori), Rekha Chachi (Babita Pandey) and Sumitra Tayi (Sonal Jha). However, Bantu grows suspicious of Mohini after witnessing a series of bizarre incidents and becomes convinced that she is a daayan (witch). When he shares his theory, the family dismisses his claims as baseless. Undeterred, Bantu delves into Mohini’s past and uncovers incidents that force the family to reconsider their beliefs. But as the mystery surrounding Mohini deepens, it becomes clear that there is far more to her than meets the eye. What happens next forms the crux of the film.