Example
SELECT Name, GROUP_CONCAT(city SEPARATOR '\n') AS city, nb
FROM
(SELECT 'A' AS Name, 'Agra' AS city, 101 AS nb
UNION ALL
SELECT 'B' AS Name, 'Delhi' AS city, 102 AS nb
UNION ALL
SELECT 'A' AS Name, 'Allahabad' AS city, 101 AS nb) AS a
GROUP BY Name, nb;