I need to access my public site from an existing domain . I have created cname records in godaddy but i am unable to access my public site. Domain name automatically redirecting me to my salesforce home screen. Let us say mahe.com is my domain in GoDaddy and I want to access my salesforce public site by hitting the URL mahe.com/AddNew
I think the only linkages required are the Domain, the DNS record and the Custom URL in Salesforce.
Have you configured all these three things?
user320 is correct. For your particular scenario, the CNAME target must be www.mahesh.com.[18charOrgId].live.siteforce.com, not test.force.com.[18charOrgId].live.siteforce.com.
Note that if you want to also serve up mahesh.com without the www subdomain, there are a couple of options:
One is to set up a 'redirect' record at GoDaddy to redirect http://mahesh.com to http://www.mahesh.com . One unfortunate 'gotcha' of DNS is that a DNS name that has other records on it, such as SOA or MX, cannot also be a CNAME record. CNAME is an exclusive record, and only one is supposed to exist on a DNS record that is a CNAME. Since mahesh.com at least has an SOA record, it cannot be a CNAME. GoDaddy and others implement a 'redirect' record as a collection of 'A' DNS records that point to a server cluster at GoDaddy that just sends http redirections to the target name when a request is made over http for mahesh.com.
The other way is to set up a certificate on the www.mahesh.com domain name, add 'A' records to mahesh.com based on the IP addresses that were reserved for the certificate, and then add mahesh.com to your organization. This requires custom https domains to be enabled, which is something that you have to request in Summer '14, but it is automatically enabled when Salesforce Communities is enabled in your organization in Winter '15 or later.