No, Tumbbad is neither a real story nor based on real events. It is a 2018 period horror film, released in October 2018. The movie is directed by Rahi Anil Barve and Anand Gandhi and written by Mitesh Shah, Aadesh Prasad, Barve and Anand Gandhi. Tumbbad stars Sohum Shah in the lead role as Vinayak Rao.
Tumbbad follows the story of Vinayak Rao and his search for a 20th century treasure in the Indian village of Tumbbad. Even though the movie is a fictional horror movie, it takes inspiration from Maharashtrian folklore, elements from various mythological tales and themes of greed and ancient cultures.

Plot Summary
The film opens with a mythological prologue: The Goddess of Prosperity gave birth to millions of gods. Her first-born, Hastar, steals all her gold and is attacked by other gods. The Goddess saves Hastar but banishes him to her womb forever, decreeing that he must never be worshipped. However, the defiant villagers of Tumbbad built a temple to Hastar, cursing the village to endless rain.
Cut to 1918 when a young Vinayak lives with his mother and brother Sadashiv in a crumbling mansion in Tumbbad village. Vinayak’s mother is the concubine of a local lord, Sarkar. Vinayak becomes obsessed with the rumors of a hidden treasure guarded by Hastar. After Sarkar’s death, Vinayak’s mother flees to Pune with her sons after stealing a gold coin from Hastar’s loincloth.
Vinayak returns to Tumbbad in 1930. Through devious machinations, he figures out the way to extract gold coins from Hastar’s loincloth without waking him. Vinayak exploits this and becomes wealthy. In the process, he becomes cruel and even more greedy. The cycle of greed extends across generations, leading to horrifying consequences.
Facts About The Film
Tumbbad is not a fictional village. It is a small hamlet located in Maharashtra’s Konkan region, specifically in Ratnagiri’s Khed region. Parts of the film were shot in Tumbbad for authenticity. Even though the locals make claims regarding a hidden treasure and ancient gods, there is no historical evidence for the same.
Hastar finds no mention in Hindu mythology or any religious texts. The movie cleverly explains this by saying that the gods erased all mentions of him.
Bottom line is that Tumbbad is an original mythological fantasy exploring human greed, rather than a retelling of real events.