I have set the A-Record of the domain to the Elastic IP of the EC2 instance.
I have set the inbound HTTP rule under the security group of my EC2 instance to port 80 and allowed from anywhere.
What else is needed? I waited for 24 hours incase of any propagation issue. But nothing. HostGator just prompts me to change my nameservers "NS1.HOSTGATOR.COM" and "NS2.HOSTGATOR.COM". But I thought I did not need a hosting package to reroute my domain to an EC2 instance. All I did was "park my domain".