Nikki Galrani has a sister, Sanjjanaa who is also an actress. Nikki Galrani did her PUC from Bishop Cotton Girls College and later took up a course in fashion designing. She said that she did science in PUC because her parents and sister wanted her to become a doctor but that they later let her pursue designing. She then did modelling and appeared in many advertisements.
In January 2013, Nikki was chosen to play the lead role in Ajith, the Kannada remake of the Tamil film Paiyaa, after an audition. Later, Nikki Galrani signed her first Tamil film, Yagavarayinum Naa Kaakka and her first Malayalam film 1983. Though it was the last film she signed, 1983 released first and became her debut film.
Even before the release of her first Kannada film, she has been signed for three more Kannada films.