I read in an article that the big "RAAZ" was that Niyati's love liked somebody other than Niyati, a girl named Saniya. Niyati and Shourya do get married, though, because Padmadevi is close to dying, and getting Niyati married was her last wish. So Niyati and Shourya do marry, but he says that this relationship is only for show and that he doesn't love her, and that he still likes Saniya. But then Shourya falls in love with Niyati. And then a while later Shourya dies.
Here is the rest of the story:
https://www.indiaforums.com/forum/kulvaddhu/471056/concept-and-story-kulvadhu-girl-reevaled
Read this!!! It is REALLY interesting!!