The easiest way to do this is to get the maximum dateout
for each branchid
and check that it is more than 36 months in the bast:
select b.*
from branch b join
(select branchid, max(dateout) as maxd
from toolorder
group by branchid
) tob
on b.branchid = tob.branchid
where MONTHS_BETWEEN(sysdate, tob.maxd) > 36;