How to create reverse DNS record in bind?

How to create reverse DNS record in bind :

Used Environment : RHEL 6

Steps followed :

1. Add following lines in /etc/named.conf :

---------
zone "0.168.192.in-addr.arpa" IN {
type master;
file "0.168.192.in-addr.arpa";
allow-update { none; };
};
---------

2. Create zone for this reverse record :

-------------------
$cat /var/named/0.168.192.in-addr.arpa

$TTL 600
@ IN SOA ns1.example.com. host.example.com. (
2012013001 ;Serial Number
86400 ;refresh
7200 ;retry
3600000 ;expire
86400 ;minimum

)

0.168.192.in-addr.arpa. IN NS ns1.example.com.
0.168.192.in-addr.arpa. IN NS ns2.example.com.
201 IN PTR example.com.
------------------

Testing :

-----------------------
$dig -x 192.168.0.201 @localhost

; <<>> DiG 9.7.3-P3-RedHat-9.7.3-8.P3.el6_2.2 <<>> -x 192.168.0.201 @localhost
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 17992
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;201.0.168.192.in-addr.arpa. IN PTR

;; ANSWER SECTION:
201.0.168.192.in-addr.arpa. 600 IN PTR example.com.

;; AUTHORITY SECTION:
0.168.192.in-addr.arpa. 600 IN NS ns2.example.com.
0.168.192.in-addr.arpa. 600 IN NS ns1.example.com.

;; ADDITIONAL SECTION:
ns1.example.com. 86400 IN A 192.168.0.201
ns2.example.com. 86400 IN A 192.168.40.34

;; Query time: 0 msec
;; SERVER: ::1#53(::1)
;; WHEN: Wed Feb 22 15:00:32 2012
;; MSG SIZE rcvd: 137
---------------------------

DB of the zone example.com looks like :

--------------
$cat example.com
$TTL 24h

;
; zone data file
; comments can appear on any line after a semi-colon
;
example.com. IN SOA ns1.example.com. root.mail.example.com. (
2012013001 ; last updated January 30th,2012, once
24h
2h
4w
4d )

example.com. IN NS ns1.example.com.
example.com. IN NS ns2.example.com.
example.com. IN A 192.168.0.201
mail.example.com. IN A 192.168.0.201
ns1.example.com. IN A 192.168.0.201
ns2.example.com. IN A 192.168.40.34
www.example.com. IN CNAME example.com.
wwww.example.com. IN CNAME example.com.
ww.example.com. IN CNAME example.com.
example.com. IN MX 0 mail.example.com.

--------------