@redi = $responsetextall[$i][$j]{set}{Client}{redirect_uris}

##</code><code>##

@redi = (
    [....],
);

##</code><code>##

@redi = @{$responsetextall[$i][$j]{set}{Client}{redirect_uris}}

##</code><code>##

$redi = $responsetextall[$i][$j]{set}{Client}{redirect_uris}
# and then...
for my $i (0..$#$redi) {
    $worksheet->write($r, 6, [$redi->[$i]]);
}