The 34-year old actress was recently rumoured to be abusing unnamed illegal substances.
Speaking to The Times of India, she said: "I don't do any of the things that they accused me of doing and in no way could they have proven it otherwise.
"I'm happy that the truth is out in the open."
She added that the false allegations had been started by "one Delhi-based person".
Rani Mukherjee has won a leading role opposite Bollywood icon Aamir Khan.
The actress last acted with Khan in the period drama Mangal Pandey:The Rising in 2005.
In an interview with Hindustan Times, she said that the new project, directed by Reema Katgi, is "more about [Aamir and I]".
According to widely-publicised reports, Priyanka Chopra and Katrina Kaif were also competing for the role.
However, Mukherjee added that she also had other major Bollywood actors in her sights.
"I'm going to meet Shah Rukh and tell him that he better start a film with me soon because I'm missing working with him."
