Hi @Lital Raanan ,
Only global Administrator or subscription administrator can delete a tenant on azure (https://learn.microsoft.com/en-us/azure/active-directory-b2c/tutorial-delete-tenant) additionaly a Security Administrator cannot grant another user the Global Administrator role in Azure. Only Global Administrators and Privileged Role Administrators (https://learn.microsoft.com/en-us/entra/identity/role-based-access-control/permissions-reference) can delegate administrator roles.
The option that you have if there is nobody with this priovilede is create a support ticket in help & support
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