yes for rishabh family comes first. whenever he was confused between preeta and his family, he chose family. his heart wanted to choose preeta though.
and karan does whatever he thinks he should do. he is all about himself. if he thinks he should do something, he will.... at any cost.
Yes, they are like that.
I just want to add that Karan doesn't do what is good for him only. He does what he thinks is just. He truly believes that he brings justice to his father. He wanted justice for his brother as well. Even if it hurts him or other people. At any cost. That is true.
In my opinion, If we put aside Karan's methods (which I don't approve) then Karan is more honest then Rishabh. Rishabh did the same thing after Karan ditched Preeta. He stayed with a family after the engagement. He stayed with the family after Karan's betrayal. He knows that it's wrong but prefers to support the family. If it was Rishabh who ditched Preeta (hypotetically, of course😆) Karan would beat him up and made him plead for forgiveness at Preeta's doorstep. That is the difference. And personally, I like Karan's pov better than Rishabh's.
I want to make it clear that I am talking here only about this specific character's trait not the methods , or situations, or the entire character.