If u see how the recent events have panned out, Adi is obsessed with that girl at this young age and does whatever she says. He impersonated Raman's voice and the police came home. After that he used Raman to lie to ishita and got the girl home- how did her father permit? On top of that he is an investor!
Adi has done several things to ishita incl blaming her for drugs overdose which still Raman does not know and he kinda blamed Ishita for it...plus due to his sucide crap, she lost Ruhi custody... in fact she is more confident with Ruhi, Ruhi knows right from wrong and does not fall for what anyone says...