Dhaani loves Viplav but not ready to confess. I feel Dhaani had bad past which led her not to put viplav in trouble by accepting his love. She loves him so don't want to create troubles for Viplav and his family.
In one of the previous scenes, Dhaani was deeply hurt and started crying when Viplav called her killer. She might have killed someone in her past to protecting herself and to hide their identity Dulaari and Dhaani are living in aashram away from the people. So if Dhaani will marry Viplav and if everyone come to know the truth that will spoil Viplav's family name. So before that she has to tell him about her past.
Even Dulaari don't want to get married his daughter to Viplav as he is from a big and rich family and she might have fear that Viplav will leave her when he get to know about Dhaani's past.
As we all know Viplav won't leave like that and in extreme pressure from Viplav Dhaani might open her past and tell him the reason for not accepting his love. When Viplav come to know about this, he will not leave her and try to get her out from that case and prove her as innocent. As Viplav is already a lawyer we get see him fighting for Dhaani's case. I expect this to happen in future track as we didn't see viplav handling any other cases after that aashram case. So with this he might prove his talent as a good lawyer and achieve his goals as lawyer.
When Viplav get Dhaani out from murder case, she might say ok to marry Viplav. Viplav will succeed his getting his true love from Dhaani.
What say Guys??? You all can share your opinions on Dhaani's past or the reasons for rejecting Viplav's love