There is no problem to use your web hosting account at Rebel Networks with more than one domain name.
If you wish to have more than one unique website hosted on your account, you can purchase an Addon slot from your Customer Area > Order Extras > Addon Slot.
Please note that the Addon slot does not include a domain name. If you wish to have a new domain name, you have to order it from your Customer Area > Order Domains.
After you purchase the addon slot and the domain name, you have to add the domain to the slot from your cPanel > Addon Domains.
Alternatively, if you don't want to have separate websites but just separate domains which load the same website, you can park your existing domain names to your primary one. You can park your domains from your cPanel > Parked Domains.
If you are having problems using your account with more than one domain at your current host, you can sign up for our cPanel hosting package. Rebel Networks' support team will happily assist you with configuring your account to work with more than one domain.