How about this for revenge: Jai Walia is a RICH guy. And RICH people like him can do anything at any time as they have way too much power. I have a few suggestions:
Get Pia, Jigs and Karuna kidnapped and torture them so they die a slow death. But before he leaves them to die, get Bani's dvd from her and make sure any evidence is destroyed. And then buy the judges to judge in favour of Bani or JW knows that on Holy Bani was with him the whole day. So he can get Tarun to fight Bani's case. Coz as we know it Tarun loves her and will do anything to save her. Even tho he's sick JW needs his help right now.
Second suggestion: Rano, JW, Pushkar and Aditya get together to fool Pia and get her to confess her evil plan and reveal that Sahil isn't dead after all and this was only part of the plan to get rid of Bani (b/c we all know Sahil isn't really dead, after all this is a drama and no one ever dies in these. He'll be back eventually). Anyways, Jai should tell Pia that he's willing to give her a chance. Pia the pea-brain will let her guard down and think she's won the battle. (not so fast tho witch). Anyways, after a week or so, he should tell her "Oh Pia, i'm having such a good time with you. Why didn't I give you a chance earlier?" He'll get her hopes all high (just to let her majorly down tho). Then he should ask her, how did she ever come up with the plan to send Bani to the asylum and how she went about doing it. Now while Pia is telling him all this, he should either secretly be taping her or have the police officer who arrested Bani, hiding in the room somewhere and listening. Then he can come out and arrest Pia for misleading and tampering with law-enforcement. And of course have Pia reveal the biggest truth of all "Sahil is alive" and name all her partners involved as well. The police will then arrest Sahil, Pia, Jigs and Karuna for purposely misleading a police investigation and stuff. And this can all start with Rano secretly telling Jai and Masi everything she heard from Jigs, Pia and Karuna that night.
After this, I hope Rano divorces Sahil, Jai kicks out and disowns Jigs and her no good worthless shit-head son Sahil and kills Pia's child and let Pia wither away in jail. Happy Ending =D