Nikki Galrani is the younger daughter of Manohar and Reshma Galrani born in Bangalore and is of Sindhi extraction. She has an elder sister Sanjjanaa, who is also an actress. She was educated at Bishop Cotton Girls School, Bangalore. Thereafter she did her PUC from Bishop Cotton Women's Christian College, Bangalore 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 early August 2020, Galrani tested positive for COVID-19, and recovered near the end of the month.