Roy had made the remark at a public meeting earlier this month.
"I have filed a defamation case. The matter is sub-judice. Please wait for the verdict. I have full faith in the judiciary. People of Bengal have already given them a befitting reply in the ballot box, now wait for the court to do the same," Banerjee, who is also Trinamool Congress'youth wing chief, told reporters.
"This is an attempt to destroy my goodwill with lies. If any allegations are proved correct, I will quit politics. Else Mukul Roy should leave the state," Banerjee said inside the court.
Last month, the court had restrained Roy from making comments against the West Bengal Chief Minister Mamata Banerjee's nephew regarding two organisations Biswa Bangla Marketing Corporation Limited and Jago Bangla Media Private Limited.