Members of the Shri Rajpur Karni Sena, an outfit of the Rajput community, gathered at two theaters in the city at 11.30 a.m. and tried to stop the screening of the film.
The protestors became violent and pelted stones, breaking glass panes of Trinton Mall in Jhotwara and Vaibhav complex in Vaishali Nagar, police said.
Police baton charged the mob resulting in minor injuries to few protestors.
"We first tried to speak to them and tried to pacify them. But seeing the protest turn violent, we were forced to resort to 'lathicharge' (baton charge). We have arrested 20 members of the Karni Singh Sena for disturbing peace, " a police official told.
B.S. Shekawat, a member executive committee of the group, said: "We were protesting against some facts shown in the film about Rajputs that we think are totally against our traditions.
"The film shows a Rajput girl being crowned as a ruler even though her father is alive. It is completely against our tradition, " he said.
"How can the crowning ceremony take place when the father is alive? Especially for girls?" he asked.
"We want objectionable scenes to be removed. It really hurts the sentiments of our community, " Shekhawat said, adding that if the director of the film fails to do so, then more such protests would be organised.