Since its a show so ishra will be together at some point of time. But looking at the current situation i think mani is far better...yes i agree he can never love ishita that passionately like raman but he will never hurt her this badly either...mani took care of his sister's children like his own and unlike raman he never married or faked someone as his wife just to give them mother's love..ishita came in his life due to circumstances and she took care of aliya as her mother but didn't faked her relationship with mani ( though may be because aliya was grown up enough to understand this).
But raman couldn't take care of his children single handedly...when ruhi was samall his parents took care of her and later he married ishita to give ruhi the love of a mother...later in case of pihu too he couldn't take care of her single handedly...though he didn't marry but he faked his relationship with womb and made her as pihu's mom...and i don't think i need to voice out what these situation means.Now raman wants to marry womb to permanently shut the door on ishita and make womb pihu's legal mom...and he has no intention to tell pihu about ishita's identity...when he assumed ishita as dead he hide her identity may be because of his guilt ( though it is yet to be shown) and now he is hiding it because of his anger but the fact is he denied ishita her rights.Looking at the recent behaviour of raman i am sorry to say but mani seems a better option for ishita...though he knows ishita can never love him but still he supported her and never forced himself on her...and mani has no past baggage either...where raman's actions always made sure his ex-wife remains around him..so ishita has no other option than sharing space with her.P.S. No offence to anyone just my POV