The film is loosely based on the life of Gangubai Harjivandas, popularly known as Gangubai Kothewali, whose life was chronicled in the book Mafia Queens of Mumbai written by S. Hussain Zaidi.
Ganga Harjivandas (Alia Bhatt) belongs to a family of lawyers. Like every other teenager growing up in small-town India in the ’50s, she’s in love with Dev Anand and wants to run away to Mumbai to become a Hindi film heroine.
She elopes with her lover Ramniklal (Varun Kapoor) with plenty of jewellery and money but he isn’t what he seems. He sells her off to a brothel for a thousand rupees and runs away. Ganga is forced by brothel owner Sheela Bai (Seema Pahwa) to take to the life of a prostitute.
Ganga accepts her reality but can’t see herself as a victim. She vows to oust Sheela Bai soon and take over the whole of Kamathipura one day. And she manages to do it with the help of mafia don Rahim Lala (Ajay Devgn), who accepts her as his sister and stands behind her in every difficulty.