I started watching again , but it's a loooong gap.so probably for some reason Karan was in jail (for Akshay s murder may be) , he was blackmailing sherlyn as he knew the truth of her pregnancy. Sherlyn killed him n blame went to Karan..preeta helped Karan prove innocent ..he was acquitted ..may be during the jail period he realized she loves him..they hugged when the court set him free..n they were Normal married couple after that....I was watching some of these epis, that's all I could gather
Haan preeta also told him that we know how sherlyn is but the family doesn't.