This show is pretty predictable, I think I know why Mihir is acting like this with Tulsi and the family. Mandhira has Karan and Nandinis Son or knows where he is, and I think Mihir is acting to find out where the child is.
What else could be the reason, a few episodes ago he would die for tulsi and now over some stupid excuse of leaving him in jail he loves Mandhira, its all act.