Different Terms&Conditions on multi-site
In Drupal 7 Domain Variable module will help you, in Drupal 6 this is not supported probably.
Domain Variable:

This module aims to be a replacement variable handling module for Domain Access, allowing mixed variable realms (domain x language) to be configured.
In other words, it allows setting different variable values for each domain and for each language at the same time.
This module supports almost all of the functionality provided by Domain Configuration, Domain Settings and Domain Theme. Differences are listed in the documentation.