This is what I think will happen:
RagNa will probably be endgame, but I think they might bring in another angle: Prem. I have always wanted them to make Prem a better person and I have a feeling they are going to do this with showing that Prem falls for Kalpi. Prem & Kalpi might not be endgame, but this is probably something that they might do and something that would be nice. If no romantic angle, I think they will show a friendship. Here are my reasons:
*They are not going to only show RaKhj, while Kalpi sits around fulfilling her Aai Ka Sapna with on kind of romantic angle. The writers obviously want to drag this track, and showing Raghav, Kalpi, and Paakhi bumping into each other is going to get old fast.
* Kalpi has no one to support her. Her parents are no help at all, and Raghav is not doing a Greta job supporting Kalpi( he saves her and will continue to, but he is not supporting her to go on like a friend) I know Prem is going to automatically support Kalpi because that will take some time. But if he falls for Kalpi or becomes her friend, he will surely support her and really encourage her.
* And who doesn't want to see Prem become nice
But I just hope they don't show him being obsessive. That would be horrible,Prem seems like an obsessive kind of character. But I hope they don't go this way,