$string = "(1,2,3,<4,5,6>),more";
my @line = split(/,(?![\w,]+[>)])/, $string);

print Dumper(\@line);

##</code><code>##

$VAR1 = [
          '(1',
          '2',
          '3',
          '<4,5,6>)',
          'more'
        ];