Yes! Domains which are purchased through other vendors can be used with Zoho Sites. All you need to do is subscribe to one of our paid plans, if you are using a free site. Then verify ownership of your domain.
Log into the domain vendor's portal and use the domain forwarding option. Forward the root domain name example.com to www.example.com (with the www).
Create a CNAME Record with host name www and point it to zhs.zohosites.com.
To add your own domain to your Zoho website:
Open the Manage menu, and select Settings from the Manage menu.
Click on the Domains option from the menu on the left.
Click the Add domain button.
Click the Map your existing domain button.