The purpose of this study is to evaluate how well JNJ-79635322 works (efficacy) in participants with Relapsed or Refractory Multiple Myeloma (RRMM; a cancer that forms in a type of white blood cells called a plasma cell. Cancer is called relapsed if it comes back after treatment and is called 'refractory' if does not respond to treatment) who have received at least 3 prior lines of therapy.