Hello,
Symantec Quarantined certain files probably they may be infected or may be they are threat.
However, Question arises why are you trying to restore these files?
Do you think these files are not malicious or they are False Positives?
I would recommend you to Submit these files to the Symantec Security Response Team and get a report of the same. Probably they are really Threat.
Here are few Articles which you may follow:
Using Symantec Support Tool, how do we Collect the Suspicious Files and Submit the same to Symantec Security Response Team.
How to troubleshoot FakeAV if it is not detected
If incase, you think these are not Threats and want to submit these files to the Symantec Security Response Team as False Positives, here is the website:
Again, here are few more articles which may help:
Restoring a false positive from the Symantec Antivirus quarantine
Restoring a false positive file detection from the Symantec Endpoint Protection quarantine