My website do not open administrator login instead it redirect me to the home page I have to repair error by using cpanel any body have suggestions
This problem is likely caused by a security plugin that was installed on your Joomla website - in most cases it is Admin Tools, in some cases, it is a different plugin such as JSecure. We have explained how to fix the problem in the case of JSecure here.
Since you already stated that you don't have JSecure installed, then I would say this is caused by Admin Tools - either disable the Admin Tools plugins from phpMyAdmin, or rename all the Admin Tools folders in your filesystem to _old (just append _old to the folder name).
To add to what @itoctopus said, if you're running Akeeba Admin Tools, go to Admin Tools then go to Web Application Firewall. Then click on Configure WAF and under Basic Protection Features tab check to see if Allow administrator access only to IPs in Whitelist is set to Yes. If it is, you can set it to No or add your IP to the white list.