This theory is based on the following things
1. Never ever once the mention of Kiran Singhania name bring guilt or remorse expression on his face.he is casual while talking to Aditya about Kiran.
2. The raaz has only to do with Banis identity not Pia or Rano.
3. Jay also gave money to Nishikant on loan coz he doesnt want him to launder away Banis money.
4. the accident date and Kirans death date are not the same.
5. It is 100% banis real mom who died in the accident and the remorse of depriving a child of her mother made him to take the decision of not marrying and that can be reason he is fond of supporting the orphan children (pushkar)
6. when jay said that he earned this money with his hard work, Roshni gave her a snickering look.
7.The reason of Roshni's coming back maybe to get some money from Jay from Banis wealth,or otherwise blackmail him into getting married to her.
8. Banis mom can be one time Adityas friend who became pregnant but before she could tell him he got engaged to jigyasa.And Jay made all these arrangements for her child to be brought up by Dixits as Kiran was his friend and they needed money so they agreed.
9. since jay knows all the secrets Nishikant send his daughters to him after his death coz he knows jays conscious wont betray him or his daughters
10.the diabetic part can be coz of jay keeping track of Kiran to make sure that Adityas daughter is well taken care of.
11. If Bani is Adityas daughter then it is okay for Jay to get married to her coz Adi is not related to Jay by blood ,and only this raaz will change all the relations in the house.
12.I dont think Jay is a kind of person who gets scared of someone being killed in an accident which was a mistake.it is only the peace of each and every member of the household that he wants to hide this raaz at any cost.
13.Banis real mom remained quiet and left Aditya ,they are showing the same personality trait of sacrifice in Bani and her class now.
What do you think guys think out there? please comment.
I think i am gonna become detective one of these daysš