A new version of aria2 is now available and I have created the rpm for this version too. It was compiled on centos7. Download link for aria2 1.35.0 rpm is given below:
gpgcheck have to be turned off because rpm is not signed. Run following command to install aria2 :
Install the rpm using:
yum --nogpgcheck localinstall aria2-1.35.0-0.x86_64.rpm
You are done. Now you can use aria2 on your Centos.