Is that her bio father?

Yes, he had some sort of amnesia, so he doesn't remember that he dated Camila's mom and had kids, Camila is wearing the ring that he gave to her mother
(▰˘◡˘▰)

will his memories come back and start remembering his past romance with Camilla's mom?

iirc yes. he would insist camilla to stay with him (but camilla won't tho she would visit once in a while bc she has another lil bro there hehe

Ravi and Camila are half-siblings. Ravi knows this but he didn't tell Camila because he didn't want her to feel like they were "less" siblings and was afraid that Camila would leave him ಥ_ಥ. They are 5 years apart, so Ravi remembers Camila's biological father. As someone already said in another spoiler Duke Escra was with them for a year, then he lost his memory AGAIN and disappeared, leaving a woman who is already poor with a newborn.He never asks what happened during that time, he didn't even tell Ravi that he lost his memory and didn't remember the year when they met. He only knows that Camila is his daughter, and he wants to take her home, he is even "willing" to accept Ravi if it means having Camila because he knows that Camila wouldn’t be able to abandon her brother. At no point does he stop to think about Ravi and how his disappearance could have affected him even if he was not his biological father. He didn't even realize that his youngest biological son was being mistreated until Camila exposed the nanny, but he criticizes Duke Sorfel because in the past the servants mistreated Camila. Like I said, he's trash.

Her family tree is really complicated