By episode 264, the show is deep into the conflict where Manik has pushed Nandini away to protect her from Kabir's threats. Nandini is hurt and confused, believing Manik never truly loved her.

It sounds like you're referring to of the Indian television series Kaisi Yeh Yaariaan (season 1).

Here’s a quick breakdown of what happens in that episode, as it was a pivotal moment in the Manik-Nandini track: