Russell Crowe will get arrested, as long as she does not change her mind and decide not to press charges. He will be arrested, but he might not get charged or spend time in jail depending on what the officers find out when they investigate this police report that she filled.
Crowe will probably get arrested but it will not lead to any serious charges seeing as he's a famous actor and has a lot of money. Unfortunately, the justice system is rigged against poor people and he is not one of them. He will sweep this under the rug fairly easily.
According to reports, Banks became abusive and threatening when she attended Russell Crowe's party as a guest of a mutual friend. Allegedly Crowe physically removed her from the room, a Beverly Hlls hotel hotel suite, after she smashed a glass and threatened another woman. If this is true and there were plenty of witnesses, there would seem to be no grounds for arresting Crowe.
Many wealthy stars like Russell Crowe commit horrendous acts and are never charged or they are given much less harsh sentences than the general public. The people like Azealia Banks who originally file charges against wealthy individuals are often persuaded to drop charges in exchange for some type of monetary arrangement.