Myslím, že toto je dotaz, který hledáte:
SELECT t1.branch_name,
COALESCE(SUM(send.vqty), 0) AS send,
COALESCE(SUM(receive.vqty), 0) AS received
FROM t1
LEFT JOIN t2 AS send on t1.id = send.VBRNCH
LEFT JOIN t2 AS receive on t1.id = receive.VTOBRN
GROUP BY t1.branch_name