You are required to register at Sybase to download this driver, once you have registered and login into Sybase you will need to " Search for a specific EBF/MR #" and enter 16903 in the search box to download this file:
Or you can copy the Sybase jdbc drivers folder, jConnect-6_0, from this path /opt/Symantec/simserver/collectors/drivers if your SSIM installation is v4.6 that was not upgraded from SSIM v4.5. Both of these sets of drivers are platform independent, you can copy them to Windows and use them.
If you have tried to download from Sybase and the SSIM v4.6 appliance and still cannot get the drivers you can contact support and support can supply you with a zipped file that contains the Sybase jdbc driver files.
Please refer to these Knowledgebase documents for steps to setup the SEP Sensor to use the embedded Sybase database: