Data conversion ("yyyy / mm / dd") to ("dd / mm / yyyy") [duplicate]

I am using a field of type Date in the file HTML , to facilitate the selection of the date, however it will save to the bank in American format yyyy/mm/dd I made the following query to transform this data and show dd/mm/yyyy , but it did not work:

$seleciona= mysqli_query($conexao,"
    SELECT TO_Char(r.Data,'dd/mm/yyyy'),r.CodReuniao Datas
    FROM reuniao r
    group by TO_Char(r.Data,'dd/mm/yyyy')
    order by Datas ASC"
);

Do you have any syntax errors?