Whether you are a VAR or not, your InterBase product you received contained a serial number to register your InterBase product. The difference for VARs being that they get a .SLIP file, which means they do not have to register to run InterBase.
Registration is REQUIRED to get to the registered user downloads page however. So, all VARS need to do is register the serial number they originally received to get to the registered users downloads page. If you have lost the registration card originally included with your InterBase product, you may contact Borland support and provide your .SLIP file to determine your registration serial number.