You will need to pull a license.xml file from teh current IPO with R10 manager.
that gets uploaded to Avaya 1 Source so you can get the quote to upgrade. If IPOSS, you will be prompted to enter the Contract number for the free upgrade.
You will get new PLDS licenses for R10
Here is a good document.
https://avaya.sharefile.com/d-s38cbeb4d0904882a