In the American culture, a brother or sister can talk to someone they know to give you a job. If you're into business, they can help your business to get contracts. If they know someone who can promote you, they would do that provided they have confidence in you. This is their way of helping each other. If one owns a business, he may employ his (or her) brother as well.
However, in Murica, siblings don't give money to each other. Their work habits prohibit them from throwing cash at each other. It seems the Malik guy was expecting Barrack to throw money at him, and when he didn't get it, he is b*tching. What a loser! Go and prove yourself instead of expecting a man - who was never raised by your father - to throw money at you.