What will be that worst which even the villain did not know?
Aditya may not be Avantika's son. Aditya maybe Dewan's illegimate son. Must have been exchanged with Avantika's dead son.
Preeti must be knowing her father's secret. And he must have created all that misunderstanding to save himself from avantika's wrath.
Or Aditya maybe the illegimate son of the brother also. The brother could have an affair with Latika's mother.