use strict;
use warnings;

my %r_name = (
    a => [ 1, 2 ],
    b => [ 3, 3 ],
    c => [ 1, 6 ],
);

my @result = grep {$r_name{$_}[0] eq $r_name{$_}[1]} keys %r_name;
print @result, "\n";
[download]

Result

b
[download]

Note for next time: It is considered impolite to edit your post in a way that invalidates existing replies. Leave the existing text. Add a clearly marked UPDATE section.

Further to BillKSmith's reply:   Please see How do I change/delete my post? for site etiquette and protocol regarding post changes.