I believe there are many twists and turns about to come in KS. I think this is how the story will progress-
We now know that Aditya is behind the attack on Jai Walia. But what about his motive? I believe it was he who was responsible for the incident at Park Road and not Jai. Remember the mechanic who got beaten by Jai Walia, in happened in front of Aditya and the next day when curious bani went to search him, he had disappeared. Maybe Roshini knew and blackmailed Aditya. Also, roshini coming back means that the actual truth may come out. I also think Jai-Bani will be back together when Jai will question her about Pushkar's name listed as the child's father. Bani may unintentionally spill her feelings that she is in love with him. Pia and Jai will not be back together and while working with Jai pia will realize how Jai has changed and loves her sister bani.
I also believe that when Aditya will meet with that man again Pushkar will see this and will inform Bani who in turn will return to Walia house to uncover the truth and will find out about Jai's innocence and slowly their relationship will come back on track. With Bani revealing the truth in front of everyone and unmasking the true villian.