He can do his best to hire a lawyer - call at least 10 and get prices from them. If he cannot afford to hire a lawyer, then he needs to bring proof of his income to court as well as the information on the lawyers he called and the prices they quoted. If he is indigent, he is entitled to a lawyer but many judges baulk when a person makes bond because that person can work to pay a lawyer. Most lawyers take payment plans.
Over the last decade or so, many States have adopted rules that allow a Court to deny court appointed counsel if bond is posted. In Oklahoma, the Oklahoma Indigent Defense Act sets forth the rules governing court appointed counsel. These rules are vey similar to those in my home State, Florida.
With regard to your question, the Oklahoma rule states: "If the defendant is admitted to bail, and the defendant or another person on behalf of the defendant posts a bond, other than by personal recognizance, this fact shall constitute a rebuttable presumption that the defendant is not indigent." In plain English, this means the Judge can deny a court appointed lawyer because bond was posted, but you can prove to the Judge based on other facts that there is not money for hiring a lawyer.
The previous writer's answer of getting price quotes from a number of lawyers and showing the Court they are unaffordable based on assets is exactly right. Be prepared, however, for the Judge to be very concerned with why your brother does not work, gets to live in a domestic home, gets bonded out and still claims poverty.