Mandakini was born as Yasmin Joseph on July 30, 1969, in an Anglo Indian family in Meerut, to a British father and a Muslim mother. She was discovered by the greatest showman of Bollywood movies of all times,
Raj Kapoor and was cast in his movie 'Ram Teri Ganga Maili' against Rajeev Kapoor, the youngest son of Raj Kapoor. She was only 16 when she acted in this movie. She was nominated for Filmfare Awards for this movie. She went into controversies from her first movie itself in which some of her scenes were termed as vulgar specially in one scene where she was bathing in a flimsy white sari and her breasts were clearly visible and the other where she breastfed a child.
She acted in some movies after that but she was in news not for her acting in movies but for her friendship with the notorious gangster Dawood Ibrahim. Rumour mongers went to the extent of stating that she has run away to Dubai to stay with Dawood Ibrahim permanently as his mistress. Later on, the rumours were proved wrong and it was known that she married an earlier Buddhist monk, Dr. Kagyur T. Rinpoche Thakur in 1990 and stays in Mumbai with her family. She takes classes in tibetan Yoga and a devout follower of Dalai Lama. She had a son who died in an accident in the year 2000. She also has a daughter.
Some of her movies are Zordar, Loha, Tezab (Special appearance), Param Dharam, Pyar Karke Dekho and many others. She left acting after movie Zordar in 1996 and settled down with her family.