Can I tame these cockatiels?

here's the problem. I have 4 cockatiels all in all. 3 of them are in a large flight cage. 1female(cinammon) and 2 males(pied, Lutino). I put nestbox in the cage. suddenly the 1 male(pied) start to attack the other male(lutino). so now I'm deciding to join the lutino to my normal gry. it has a mediun size cage.. I separate the normal gray because I'm planning to taim him, now that I will put the other lutino. can I still taim this two cockatiels??? That's my question. YES or NO.. hope you could help me.