CPC Law - Hypothetical Scenario

Suppose, Rohita files a defamation suit against Vikas for allegedly making false statements about her business online. Vikas however claims that the statements were made in a Facebook post in his personal capacity, not as an employee of XYZ Inc., which is the company that employed him at the time of making such remarks. Rohita's business has taken a huge hit due to this, and she wants Vikas to be held liable. Vikas argues that since he was acting on his own personal capacity, he should not be held liable. Considering the IT Act and the Indian Penal Code, which legal remedy would apply in this situation?