Hi ​@AKK  Welcome to the Box Community!

If you have deleted an account online, you will not be able to use the email address to create a new account immediately. As stated here in "Canceling your Box Account," and as per Box's process:

Deletion will not happen immediately; please allow time for the system to process the request.

Note:
The email address used for the free account cannot be used for any Box account until 120 days after the account deletion.

If you wish to continue using Box services with the email you initially used to sign up, please email Billing@box.com so they can assist you with reactivation.

Let us know if you have other concerns. Eager to help!