Your brother is charged with assault with a deadly weapon. He needs to hire an attorney and discuss his case wIth that attorney. If he can't afford to hire one, the court will appoint counsel to represent him.
Your brother is most likely charged with Penal Code Section 245, assault with a deadly weapon (ADW) or with force likely to create great bodily injury. ADW is both a serious felony and a strike offense that carries with it 2, 3 or 4 years in state prison.
Investigation of the complaining parties background is essential to the successful defense of this case. This case requires an aggressive and experienced attorney.