First, Make P6_REGION_ID

that will contain all Region available for your page

use this code as a source

select PLUG_NAME, ID from APEX_200200.wwv_flow_page_plugs

where FLOW_ID =:P6_FLOW_ID and PAGE_ID =:P6_STEP_ID

and select list item P6_BUILD_OPTION

that will contain all build Options available for your APP

use this code as a source

select PATCH_NAME,ID from APEX_200200.wwv_flow_patches where FLOW_ID =:P6_FLOW_ID

and make a process to update Region Build Option

BEGIN

UPDATE APEX_200200.wwv_flow_page_plugs

SET REQUIRED_PATCH = :P6_BUILD_OPTION

WHERE FLOW_ID = :P6_FLOW_ID

and PAGE_ID = :P6_STEP_ID

and ID = :P6_REGION_ID ;

end;