I dont know anything about Billotti
He was.picked becaus Castallano knew that he was going to lose atleast one of the two I cases against him and and was going to go away for life.

So Billotti was his way of controlling the family from the inside it was someone he trusted to be loyal.

Remember Ruggerio who was really really close tried to take out Gas, it was an in sanctioned hit.

Gas didn t know where Gotti stood on that hit.

Gotti should have killed Ruggerio for what he did.

Because he didn't it appeared that he either k we about or even sanctioned the hit.

Caso was he'll bent on revenge for that
That was the main reason he came after Gotti

Everyone one would have been better off had Gotti clipped Ruggerio
He died of cancer if he had the choice probably would have preferred two in the back of the head ala Sammy, never knowing it was coming.