TRAN_TYPE
----------
success
failed
123456-001
654321-001
098765-002
time out

123456-001
654321-001
098765-002

where regexp_like(tran_type, '^d{6}-d{3}$');

with your_table (tran_type) as (
            select 'success' from dual
  union all select 'failed' from dual
  union all select '123456-001' from dual
  union all select '654321-001' from dual
  union all select '098765-002' from dual
  union all select 'time out' from dual
)
select tran_type
from your_table
where regexp_like(tran_type, '^d{6}-d{3}$');

TRAN_TYPE
----------
123456-001
654321-001
098765-002