Is that possible to point like below
It sounds like you are setting this up for localhost viewing, or on a local network. My answers are somewhat specific to this, particularly the part about your hosts file.
ServerName xxx.xxx.xx.x/mysite #server ip address
ServerName takes a hostname, not an IP address or path. Try mysite.com instead.
If your Rails app is called "Projects", then this line looks correct.
Ditto, this path should match the DocumentRoot line.
and Can I access xxx.xxx.xx.x/mysite in my browser? I tries this but its doesn't work...
If you had set up the server to respond to mysite.com, and the server was running, then you would point your browser to mysite.com/ and see whatever you had configured your root path to be.
// hosts file
In your hosts file, you would put
A DNS record like this would point *from* an IP *to* a virtual host. In production, you would set up your public server to respond to your actual domain name, and you would have your DNS hosting provider point your domain to the public IP address of your actual server.