emm Vasu!I dont remember the exact date of when it aired but when little sneha was in trouble and she needs a bone marrow so prerna and bajaj passed a bone marrow test but doctor claimed that how is it possible that neither father reports are positive nor mother so prerna at the time realize that Anurag is the father of sneha..Then she keep on convincing anurag that u r the father of sneha but anurag didnt bother to all this, In the end prerna said that atleast gave a blood test, it will proof everything, and anurag did it accordingly.Then reports came, and anurag was so shocked after seeing it, then this scene took place.
Now second part.
When sneha was going somewhere in a car, she suffered through a small accident, she went city hospital and met the doctor who did the operation of her brain tumor.. the doctor started talking abt her past that how she is and how is prem..sneha asked who is prem..doctor replied prem, ur youger brother, how u forgot that only due to prem u r alive!!Sneha got a shock..then doctor told everything abt anurag and prerna relationship and told that anurag is your father... sneha wasnt beliveing all these things..she rushed to her house and then straightaway went to bajaj room, she checked some files in cupborad and in all those files she found her BIRTH CERTIFICATE and then in father's name place she found anurag name and this is the way she came to know that anurag basu is her real father.