Rajni was born in a small town called Rangapara in Assam, India. She has admitted that her interest in cinema began when she was a child. In 2007 she wrote and produced a highly acclaimed Assamese feature film Anurag, that received seven Assam state film awards. Her debut film as a director, Raag released nationwide in March, 2014 and won her many accolades. She will now be seen acting alongside Priyanka Chopra in the upcoming biopic Mary Kom which releases September, 2014.