I have bought the domain name www.rockincal.com and updated the name servers there to ns1.x10hosting.com and ns2.x10hosting.com. Also I have logged in to my X10 account management page and changed the information to Primary Domain:http://www.rockincal.com
cPanel URL:http://www.rockincal.com:2082
but, now i can't access either www.rockincal.com or
anchoo.pcriot.com
You've not made the change properly. If you want to keep both the domains, then go to cPanel and add the domain you've registered under addon domains, this way you will get to keep the subdomain as well as the domain.