He has no music knowledge as far as I know, but he has hosted musical dance shows. He has good hosting skills, which is basically what is needed.
Do you really think Ishita has much musical knowledge, despite being a singer's daughter? Even Shaan didn't make too many musical comments. Like Ujjaini said, Shaan would simply come and praise them all to the top at the end of every performance, regardless of how they sang.
In any case, I'm sure Rohit is better than Babul Supriyo as far as hosting is concerned. That poor guy seemed totally awkward and lost. Debojit seemed more at ease than him 😆😆😆