Perhaps you are looking for:

use strict;
use warnings;
use Data::Dump::Streamer;

my @ranges = (
    [
      { I => 3, },
      { I => 4, },
      { I => 2, },
      { I => 6, },
      { I => 9, },
    ],
    [
      { I => 3, J => 2, },
      { I => 4, J => 3, },
      { I => 3, J => 4, },
      { I => 3, J => 6, },
      { I => 4, J => 0, },
      { I => 4, J => 1, },
    ],
    [
      { I => 4, J => 3, K => 2, },
      { I => 4, J => 3, K => 1, },
      { I => 4, J => 2, K => 2, },
      { I => 2, J => 3, K => 2, },
      { I => 6, J => 2, K => 1, },
    ],
    );

my $loop =0;
foreach my $rngGrp (@ranges) {
    my @ds;
    my $f=0;
    
    foreach my $rngHash (@$rngGrp) {

        my @rngList = sort keys %$rngHash;

        insert (\@ds, $rngHash, \@rngList, "line $f");
        $f++;
    }

    if ( $loop == 0 ) {
        insert (\@ds, undef, [6], "new line");
        insert (\@ds, undef, [9], "new line");
        
    } elsif ( $loop == 1 ) {
        insert (\@ds, undef, [4, 0], "new line");
        insert (\@ds, undef, [3, 6], "newer line");
        
    } elsif ( $loop == 2 ) {
        insert (\@ds, undef, [2, 3, 2], "new line");
        insert (\@ds, undef, [6, 2, 1], "newer line");
    }

    $loop++;

    Dump (\@ds);
    print "\n\n";
}

exit;


sub insert {
    my ($array, $hash, $keys, $text, $dim) = @_;
    
    $dim ||= 0;
    
    if (! defined $hash) {
        if ($#$keys > $dim) {
            $array->[$keys->[$dim]] ||= [];
            insert ($array->[$keys->[$dim]], $hash, $keys, $text, $dim
+ + 1);
        } else {
            $array->[$keys->[$dim]] = $text;
        }

        return;
    }
    
    if ($#$keys > $dim) {
        $array->[$hash->{$keys->[$dim]}] ||= [];
        insert ($array->[$hash->{$keys->[$dim]}], $hash, $keys, $text,
+ $dim + 1);
    } else {
        $array->[$hash->{$keys->[$dim]}] = $text;
    }
}
[download]

Prints:

$ARRAY1 = [
            ( undef ) x 2,
            'line 2',
            'line 0',
            'line 1',
            undef,
            'new line',
            ( undef ) x 2,
            'new line'
          ];


$ARRAY1 = [
            ( undef ) x 3,
            [
              ( undef ) x 2,
              'line 0',
              undef,
              'line 2',
              undef,
              'newer line'
            ],
            [
              'new line',
              'line 5',
              undef,
              'line 1'
            ]
          ];


$ARRAY1 = [
            ( undef ) x 2,
            [
              ( undef ) x 3,
              [
                ( undef ) x 2,
                'new line'
              ]
            ],
            undef,
            [
              ( undef ) x 2,
              [
                ( undef ) x 2,
                'line 2'
              ],
              [
                undef,
                'line 1',
                'line 0'
              ]
            ],
            undef,
            [
              ( undef ) x 2,
              [
                undef,
                'newer line'
              ]
            ]
          ];
[download]