You can now view the new Server edition by going into Server Manager. In this way you can activate Windows Server Evaluation edition to full retail edition.

Can you activate Server 2012 R2 evaluation?

For all editions, you have 10 days to complete online activation, at which point the evaluation period begins and runs for 180 days. During the evaluation period, a notification on the Desktop displays the days remaining the evaluation period (except in Windows Server 2012 Essentials). You can also run slmgr.

Can we activate evaluation version?

An evaluation version can only be activated using a retail key, if the key was from volume center then you’ll need to use volume distribution media that can be downloaded from volume licensing center.