Hi Pasindu Soysa,
according to Microsoft's licensing terms, Disaster Recovery rights are included with Windows Server Datacenter licenses. This means that you can use the same licenses assigned to the production server for the DR server without needing to separately license it.
However, it's important to note that the DR server must be in a passive mode and only used for disaster recovery purposes. Additionally, you must have Software Assurance coverage for the production server to be eligible for Disaster Recovery rights.
Regards,
Lei