Since I didn't follow much about this show before lockdown so I don't know enough about Rey's viewpoint.
But from what I've seen,Reyansh actually has a certain level of respect for Pranati.
I think that's because Pranati never came after him even though she was pregnant and also knew that Reyansh comes from a wealthy family(usually the villains use this opportunity as a trump card to make an entry as a daughter-in-law by blackmailing 😂😂😂😂). Maybe this is why everytime anyone tries to call Pranati an opportunist or a gold-digger,he gets all worked up.
Also I have a hunch that Rey might've harbored some feelings for Pranati in the past but he never bothered to acknowledge it since he isn't the type to commit.
But then again,these are all my assumptions.