use strict;
use warnings;

use Data::Dumper;

our @array  = (
   ['ashok',15,'2006-01-01'],
   ['ashokpj',15,'2006-02-01'],
   ['ravi',56,'2006-03-01'],
   ['raja',56,'2006-02-01']);

our %newest = (
   map {($_->[1], $_)}
   sort
   {
       $a->[1] <=> $b->[1] ||
       $a->[2] cmp $b->[2]
   }
   @array);

our @res = ();
push @res, $newest{$_} for
   sort {$a <=> $b} keys %newest;

print Dumper(\@res);