"To give precedence to my personal priorities of family and health, I have decided against renewing any client mandates and to exit the business of communications consultancy," she said in a statement.
"It is a painful decision, taken after much consideration and consultations," added the statement.
Niira Radia was in news after her conversation tapes leaked in the media.
"The Tata Group respects the personal wishes of Nira Radia in not renewing any client mandates. She has built Vaishnavi from scratch into the company it is today, often subordinating her personal and family interests in favour of her clients' priorities," said Ratan Tata, chairman, Tata Group.
"We regret the decision of Nira Radia to discontinue her association with the business of communications consultancy and not renew any of her client mandates," said a Reliance Indutries spokesman.
"We have enjoyed a professional and fulfilling relationship with Radia and her team over the last three years," said the spokesperson.