http://youtu.be/0J-dgqCS76c
I have a habit of skimming so I apologise if I miss anything important but basically in the first OLV NB tells Ishani that if she can get Veer to agree to marry Naina, she can go back to Ranveer. Ishani is really happy and is also able to get NB to promise that he will give all the medical details/injections so Ranveer doesn't have to be dependant on NB again.
Second OLV, they must've found out that Veer is Ranveer so NB goes back on his word. He refuses to give the cure to Ishani because Ranveer could back out of the wedding with Naina later on. He still wants Ranveer to marry Naina.
Small Rads intv which pretty much sums up the above. There's a small part where she talked about Ranveer very quietly but I couldn't understand what :(