As far as the promo goes, it seems that RK is planning his revenge……again some news are coming that RK is suffering from some life-threatening disease because of which he is planning all these so that he can create a distance between him and Madhu for Madhu's well-being ……he wants to make it look that he has betrayed her so that madhu detests him.
Seeing RK's recent change it is very difficult to believe that all these are just steps to take his revenge. But it can happen only if RK wanted to break Madhu emotionally before settling the score.
If his illness is the reason behind this, then perhaps he will go for the treatment and then that treatment might work miraculously and he will recover from it and then will want to bring madhu back in his life. To bring Madhu back in his life, he will leave no stones unturned. But perhaps it would be too late. Madhu might become ruthless & stonehearted by then.This would be the point where RK's 'junoon' will start because we know that he never gives up and fights till the end.
According to the synopsis, Madhu will be in a state of shock after RK reveals the truth and she does not believe him at first. Delighted at having completed his revenge on Madhu, he leaves her at the chawl and takes away the mangalsutra from her.
But I think that though RK will leave her at the chawl, Madhu may not return to her mother because she will never want to put her mother in misery. She will perhaps go somewhere else.
About madhu's entry in to the film industry, there can be two ways :-
1) 1) Either she will enter the industry on her own to give RK a fitting reply
2) 2) Or RK will somehow blackmail her into entering the film industry to keep her close to him when he will fail to make madhu understand the reason for leaving her before the treatment. (if he was really ill that is)