College friends Archi and Parshya, who have contrasting personalities and belong to different castes, fall in love. However, their relationship falls prey to the stringent practice of casteism.
After praying for years to Lord Vitthal, Sumitra is blessed with a baby boy. However, her nephew kills her husband and son. An agitated Sumitra goes to the temple to seek justice from the deity.
'Mantr' is journey of transformation of a preacher's son, from a state of confusion about his father's profession up to accepting the same with a faith restored.