"I have learnt through the media that the religion of the attacker has been concealed in the film by changing the name. I have also come to know through social media that his name was Naeem Khan, but in the film that character has been called Rajesh Sharma.
"If you are making a film based on real life, keep all the characters real," Swami Chakrapani Maharaj, national president of Hindu Mahasabha, told . It's a calibrated propaganda of 'tukde tukde gang' of Bollywood to defame Hindu religion, he added.
Unless the name was changed, Hindu Mahasabha workers would stage protests and won't allow film's release, he said.
"We will take legal action. I will meet the Home Minister and the censor board officials. We will do everything in our capacity if the makers of 'Chhapaak' didn't listen to us," said the swami.
Based on the life of acid attack survivor Lakshmi Agarwal, the Deepika Padukone-starrer is due for theatre release on Friday.
According to some reports, film's director Meghna Gulzar changed the name of acid attacker Nadeem Khan, 32, to Rajesh. Other reports say the name was changed from Naeem Khan to Babboo aka 'Bashir Khan', and Rajesh was the name of protagonist Malti's boyfriend in the film.
Nadeem, Naeem and Rajesh started trending on micro blogging site Twitter as soon as Deepika Padukone visited the JNU campus.
( With inputs from IANS )