If you are going to upgrade TDP for Oracle from 5.3 to 5.5.
You have to download what is called the base code, 5.5.0.0, and this code is only available via PassPort Advantage or order via IBM Marketing Rep.
The base code contains a file called agent.lic .
If you download the maintenance code from the public ftp site, you'll receive an error about missing 'agent.lic' file.
If you do have access to the PassPort Advantage, please check the requirements for TDPO 5.5 . You may also have to upgrade the TSM API.
Good Luck,
Sias