Nanda, in a lengthy Facebook post on Monday who worked with the actor on hit '90s show "Tara", accused Nath of raping her 19 years ago.
Responding to the allegations, Nath's lawyer Ashok Sarogi said, "All the complaints are false and there is no merit in it."
"A person waits for 19 years and then comes out with the case and after that to support her case, other persons join her. This by itself indicates that something is being done purposely, only to malign his image and nothing beyond that," he told reporters here.
Sarogi said they are planning to file a defamation suit against Nanda and others who have made such allegations.
"We take all these allegations as defamatory statements made against him without any reason. We are planning to file a defamation suit," he said.
He said if required, they may file a suit for the recovery of the amount for the damage caused to Nath's reputation.
Asked why the actor was not coming out in open to respond to the allegations, Sarogi said, "Everybody is entitled to put up messages on WhatsApp and Facebook and get it circulated. But that is not required to be responded immediately by the person concerned."
As and when any legal action starts, the actor will definitely come forward, he added.
Nanda gave a detailed account of the alleged assaults in her Facebook post, the latest expose in the #MeToo movement sweeping India.
Reacting to the allegations, Nath had earlier told ABP News, "Neither I am denying this nor do I would agree with it. It (rape) must have happened, but someone else would have done it. Well, I do not want to talk much about it as for the matter if it has come out, it will be stretched."
Nanda alleged that Nath sexually assaulted her on more than one occasion after he was fired from the 1993 show for misbehaving with its lead actor, Navneet Nishan.
Nishan said she empathises with the "terrible pain" Nanda has gone through. Without naming Nath, she said she also suffered because of this man's "power trip".
(With inputs from agencies.)