I have an unlimited webhosting plan from http://www.domainindia.org/web_site_hosting_india.php.
I want to give my users a registered domain name like: usersite.com and provide a cpanel to them with basic features like email, phpmyadmin, databases, filemanager (developed by me).
I'll be registering the domains myself and adding them to addon domains of my cpanel so that they can use my webspace, bandwidth and databases. This should be no problem due to my unlimited plan.
I know that the cpanel will be a shared one for all the addon domains, so I'm thinking to provide a zpanel http://www.zpanelcp.com http://www.zpanelcp.com/zpaneldemo/index.php to each user as it is free and easy also. Or develop my own basic cpanel like my3gb.com provides.
As I'm planning to develop my own hosting site in a way by providing registered webdomains, webspace, zpanel for controlling the website...
I want to know is it legal to do so?
Please give me ways to do this.
Well, first check with your hosting provider whether it is legal or not. We don't know your contract. Reselling may be forbidden.
Second, this is like saying I have a nice van, I want to open an international airline. Yes, you have unlimited domains etc. but not unlimited memory and CPU cycles. So at one point it will get slower. Also, the host may just terminate you if you get too expensive.
A Broken business model.
This is just problematic solution where weird things can happen. It might be legal, it might now. I for once doubt your hosting provider "officially" allow it. But why not go for a Reseller hosting package in the first place?
Usually when a host offers unlimited domains, that only applies for the primary user. If you're reselling the domains, most contracts usually require you to purchase a reseller plan since you are technically reselling.
While the host likely won't slam you for a small operation, if you're planning to make hosting a big deal of your company, then buying the reseller plans are a wise investment.
To use a custom control panel - you might want to buy a dedicated server or VPS and scale that accordingly since many reseller and shared plans don't allow you full root access.