Viren must be 25, Virat must be 23, Dr Manan must be atleast 27.
I would rather go with the choice that Maya might be her long lost child than ever thinking any of the main characters are her child.
Lets just say Swamini is 40, theres no option of any of them being her child. Unless the writers decided to make Swamini very old so that its okay for one of them to be her child.