T Risk Manager app customization is available under Apps>Manage your apps in Jira meniu where you should press button 'Configure':
You will be able to customize which risk columns will be visible in main T Risk Manager app window. Configuration will be the same for all Jira project and users.
Pro tip: Select only most valuable columns you need to show in main T Risk Manager app window.
T Risk Manager give other fast track ( three pre-setup default column configuration) options and drag and drop alternative to customize risk register columns.