As purely the recipient of the disc, and not the SEE license holder, you have no means of obtaining the latest version of the software from Symantec. You'd need to speak to this external company.
BTW, there is no version 10 of SEE, it awkwardly jumped from v8 to v11, so definitely best check with those doing the scanning for you.
A list of all SEE versions can be found in the Release Details secton at the bottom right of the below link:
https://support.symantec.com/en_US/endpoint-encryption.html