'Kyunki Saas Bhi Kabhi Bahu Thi 2' 21st May written update: Nandini gives Tulsi an impossible choice

In this episode of 'Kyunki Saas Bhi Kabhi Bahu Thi', Tulsi tells Nandini about her decision to bring Rio and Niyati to Shantiniketan. Nandini is shocked and reminds Tulsi about everything that has happened, but she reminds her that Rio is the heir of the house and her grandson. She asks Nandini for permission. She says she has done everything for Tulsi and never got anything in return. That's when Nandini says no other mother-in-law has done what Tulsi did for her many years ago, and now everything has changed.Tulsi tells Nandini she killed Ansh and regrets it. She asks her to think like a mother and not punish Rio and his mother, while asking what mistake they made. Nandini asks Tulsi what mistake of hers made her go from being a mother to becoming a mother-in-law. Tulsi tells Nandini she is still her daughter, which is why she killed Ansh. Nandini tells Tulsi she will never forgive her for bringing Rio and his mother.Tulsi asks Nandini why she would do that now, because she cannot leave her grandson and bahu alone just because he looks like Ansh. Nandini tells Tulsi she will make her work easier and gives her an option- choose between her or Rio with Niyati.Gayatri talks to Pari on the phone while sitting with the other daughters-in-law at the dining table. Gayatri asks Nandini to eat some snacks but she refuses. Tulsi thinks about her ultimatum. Saloni tells her that Gautam uncle has dropped Sobha aunty at the airport, while Ritik tells everyone that Munni has gone to pick up her sister who is coming for an eye check-up.Tulsi tells Ritik they should welcome Munni's sister. Just then, she arrives with her sister. Munni introduces Khushbu to Tulsi and Khushbu takes her blessings.Tulsi asks Nandini if she is still upset and she in turn, asks her why she decided to take such a big step. Just then, Sahil comes home.Niyati and Rio are looking for his favourite guitar. Their search leads them to the store room, where he stars opening boxes. There he finds a diary with photos of his father. Rio realizes he looks identical to his father and understands that Ansh is his father. He wonders why Karan told him not to ask about his real father. Rio takes the photos with him.Tulsi gives kheer to Khushbu and gifts to everyone. Tulsi is happy to see Sahil loves his gifts and asks him to have the kheer. Everyone teases him and also thanks him. Damini thanks Tulsi for the laptop, to which she tells her not to thank a mother for gifts.Gayatri then calls Sahil. Tulsi tells everyone she wants to decide about the shares and says according to Mihir, they need to start the discussion before making papers. While Dev is happy, Karan asks Tulsi to wait for Papa. Gautam tells Karan that he left because of him and they start arguing.Tulsi tells Gautam everyone must agree and that he will not go anywhere as long as she is alive. Tulsi tells them she will also take suggestions from her daughters and daughters-in-law. Nandini gets up and goes to her room. Karan goes to see her.Precap: Nandini tells Karan that Tulsi will have to decide who will stay.