With every new chapter my belief that S is P is strengthening.....P must have survived but suffered something or P must have promised V that she will leave R forever and V should not bother R in return V would grab this as he knows without P R is dead metaphorically.... The physical intimacy can be only between R and P.
But given your style this looks too cliche....so what do we have...twin sisters P and S separated at birth .. .
But I feel looking at R drastic mental illness P must have come as S....F saying S is S is little doubtful...I feel F and S i.e. P are together in this....
Whatever will wait for your twist
Since u asked this politely so.... yes pallavi and sarika are twin sisters who were lost in kumbh while getting in the boat and because raghav was driving that boat, Sarika blames him for this and have come back to take revenge of her sister. And Ved/Uncle/VD/Milind was/were chotu/s working on boat at that time so he also know all this.