Discipulus solution above is very elegant. Here's the correction of the error in your script:

use strict;
use warnings;

my $file = "input.txt";
my @data;
open (IN,"<","$file");
my $count = 0;
 while (<IN>) {
  $count = 1 if /SCHEDULE\s"(DUMMY\sCHECK)".*/;
    if ($count >= 1 and $count <= 6) {
-      @data = $_;
-      print @data;
+      $_ = <IN>;
+      print;
      $count++;  
    }
        
 }
[download]

You did not read the next line off your input file descriptor.