use strict;
use warnings;
use feature 'say';

use JSON;

my $results = {};

for my $href ('root') {
    my $by_group = {};

    while (my $line = <DATA>) {
        my ( $key, $group, $value, $version, $file, $count ) = split(/,/, $line);

        push @{ $by_group->{ $group } }, $value;
    }

    my $test = [];
    for my $group ( keys %{ $by_group } ) {
        push @{ $test }, { group => $group, values => $by_group->{ $group } }
    }

    $results->{ $href } = $test;
}

say JSON->new->pretty->canonical->encode($results);

__DATA__
bla,ABC,6.13.00,bla,bla,bla
bla,XYZ,1234,bla,bla,bla
bla,XYZ,tcsh,bla,bla,bla
bla,WEA,6.13.00,bla,bla,bla
bla,BAB,ASDAS,bla,bla,bla
bla,BAB,12312321,bla,bla,bla
bla,SADA,6.13.00,bla,bla,bla
bla,SADA,12312321,bla,bla,bla

##</code><code>##

$ perl oved.pl
{
   "root" : [
      {
         "group" : "BAB",
         "values" : [
            "ASDAS",
            "12312321"
         ]
      },
      {
         "group" : "ABC",
         "values" : [
            "6.13.00"
         ]
      },
      {
         "group" : "XYZ",
         "values" : [
            "1234",
            "tcsh"
         ]
      },
      {
         "group" : "WEA",
         "values" : [
            "6.13.00"
         ]
      },
      {
         "group" : "SADA",
         "values" : [
            "6.13.00",
            "12312321"
         ]
      }
   ]
}