This is simply my opinion, I don't wish to cause offence.

Jeevika is Maanvi's sister, her own flesh and blood. They have known each other all their lives, with Jeevika being like a mother to Maanvi. Therefore, her sacrificing her own child for Maanvi, is not as difficult as it is for Viren to sacrifice his child for Maanvi.

Viren has only known Maanvi a few years, and she is his wife's sister, not even his sister. But here he is deciding to save her life, over his own flesh and blood. The biggest sacrifice anyone could ever make.
But this also shows his love for Maanvi, he is true to his word.. He cares and loves Maanvi just as much as Jeevika cares and loves Maanvi.

I'm not saying that Jeevika's sacrifice is a small one, obviously it's not, but to me Viren's sacrifice seems just that little bit more difficult, and that little bit more honourable.

 

if jeevikas decision can be called commendable, his is larger than life sacrifice.

only proves the strength of his persona, his morals and his values.

 

i would have supported him either way, but this decision is a stronger one emotionally and am glad he made it

I hope the sacrifice is fruitful...