nandini is pooja's sister's daughter(i think)
the thing with ansh started like this:
i think harsh needed blood or sumthin and tulsi and mihir couldn't give the blood cuz it didn't match. that left sajul to do sum exploring and she got a secret dna test done between harsh and mihir which no1 new bout and the test results came out negative so she told every1 that and every1 started to be suspicious of Tulsi. then later it is shown that harsh is kesar's son b/c kesar had gotten raped by raj bhaseen who was madly in luv with kesar(kesar and raj were best friends). kesar only thought of raj as a friend and she fell in luv with anupam and married anupam. anupam leaves for a business trip which is supposed to last for a year and during that time kesar goes back to her village and raj tries to create misunderstandings between her and anupam but doesn't succeed. raj then tells kesar that there is a reunion party being thrown by their friends b/c she has cum after a long time. raj says he'll pick her up. raj takes kesar to a deserted place and there he rapes her! kesar tells this to only tulsi and kesar finds out she is pregnant! kesar and tulsi secretly file a case against raj which sends him to jail. tulsi was also pregnant at the time. tulsi and kesar give birth on the same day and at the same hospital since both of them were still in their village. raj escapes from jail and goes to the hospital where he meets kesar and tells her he is taking their son but it turns out he took tulsi's son instead since they both had sons. so kesar decides not to tell tulsi this and give her child to tulsi.
when every1 finds this out they all wanna search for the child but tulsi doesn't for sum reason. after a long time they find out that raj sold the baby to sum1 and it turns out that he sold it to aditya gujral (aditya and "his" son, ansh, had created sum problems for the virani's). when every1 finds out that ansh is their long lost son they are all happy but ansh being the rude person he is refuses to acknowledge this. meanwhile nandini cums into the house and falls in luv with karan (mihir's illegimate child who had created problems but now is verrrry swweeeeeet)who also falls in luv with nandini(karan had liked damini but gautam married her out of revenge b/c he thought that it was karan's fault that his wife teesha died). ansh also falls for nandini who is a reporter and had cum to take ansh's interview but when ansh misbehaves with her she hates his guts. ansh finds out that nandini is currently living with the viranis. ansh decides to go to the viranis and act all good and stuff. ansh wins every1 ova, even nandini b/c every1 believes he has changed. ansh creates misunderstandings between karan and nandini using his friend tanya who later (too late) takes karan and nandini's side. but by then it is too late b/c ansh and nandini get married b/c tulsi finds out that ansh is in luv with nandini and tulsi plays match maker. nandini thinking that karan doesn't luv her decides to marry ansh. but karan was only pretending b/c he didn't want to hurt his ma(tulsi accepted him). on their wedding nite nandini finds out the truth about ansh and for awhile all they show is karan crying and ansh torturing nandini.
i g2g rite now. i'll be back to update u on more!