Please refer to the article (link given below) for
1. Getting the license file for Symantec DLP
2. Checking the basic details of license file provided to you.
Once you have license file ready with you, you are ready for applying it. For applying the license file, you have to be System Administrator. There is no need for Administrator account for applying license file. You can first go to SYSTEM->SETTING->GENERAL for checking the license details that is already there in the system. You can take screenshot for future reference (see the last image)
For applying the new license file:
Make sure you have saved the .slf file on your local machine.
Go to SYSTEM->SETTING->GENERAL, Edit General Setting. You will find install license file (.slf) somewhere little down on the page (see image below).
Browse and select the license file, click on Save.
For checking you should now see the new count and/or new expiry date for licenses (see image below)
Count will be the number of license. Status will be 'OK', 'Expires Soon' or 'Expired'. Expiration will have date end date of license.