I agree with you. Nahr is always think of family and so does sal. I think sal has agreed to give baby to Tara as well.
I was so disappointed with Nahar. After all Saloni has gone through he still wants her to give the baby to Tara.
He always demand too much from her. What would he do if she can't have anymore children? If it comes to a choice Saloni or the baby - I now know he will choose the baby after all she promised to give Tara the baby. He's all talk
But you are right why don't they call the baby to be raised by both. also even though baby is given to tara it still stays in the family. Also after getting vedant Tara may ask Sal to keep the baby.
Both Nahar and Sal are portrayed very noble who always put other's happiness before their own. If Sal does not have another child I am sure Tara will give sal back her child.