CRM 2016 Import Organization Error

Hi,

I am getting error "This organization cannot be upgraded. You can only upgrade organizations that have a version of CRM that is no earlier than Microsoft Dynamics CRM 2015." while upgrading MS CRM 2015 organization into MS CRM 2016.

We have taken MS CRM 2015 Organization DB backup and Restored it on MS CRM 2016, But when we execute Deployment Manager and provide MS CRM 2015 Database its showing above error.

Please suggest...

Thanks in advance!