The below query can be useful for finding request group associated for a program.

SELECT
rg.application_id "Request Group Application ID",
rg.request_group_id "Request Group - Group ID",
rg.request_group_name,
rg.description,
rgu.unit_application_id,
rgu.request_group_id "Request Group Unit - Group ID",
rgu.request_unit_id,cp.concurrent_program_id,
cp.concurrent_program_name,
cpt.user_concurrent_program_name,
DECODE(rgu.request_unit_type,'P','Program','S','Set',rgu.request_unit_type) "Unit Type"
FROM
fnd_request_groups rg,
fnd_request_group_units rgu,
fnd_concurrent_programs cp,
fnd_concurrent_programs_tl cpt
WHERE rg.request_group_id = rgu.request_group_id
AND rgu.request_unit_id = cp.concurrent_program_id
AND cp.concurrent_program_id = cpt.concurrent_program_id
AND cpt.user_concurrent_program_name ='Full/Long Program Name';