As far as I've understood, Jinyao and Yi yun both applied to get a baby through a surrogate in a foreign country. But Jinyao had to have this baby secretly, so he searched for the only other asian person in the hospital records who also applied for a surrogate (which happened to be yiyun) so he switched his seed with yiyun's. So Yiyun was the one who took care of the surrogate mother and rourou thinking rourou was his own son until Jinyao shows up a few years later. And i think Jinyao ordered his people to keep track of Yiyun and rourou to see how his son would grow up.
Apparently he did not get rid of Yi Yun's
He said he has to make it up to him because he made Yiyi believe Rourou is his and also made him raise the child (doesn't change the fact what he did is wrOng though, but plot)
Then later he discovers that someone who wanted to scheme against Jinyao (assumingly) stole Yiyi's seed thinking it was his
Basically they fabricated so many things plus scheming relatives and inheritance and cute baby Rourou and FengYi ship ٩(๑❛ᴗ❛๑)۶
Can someone just explain to me how rou rou is jinyao son and how yi yun has custody of him?