Project Type Bill Rates coping to Project and Task if i over ride at Project level it is not changin

Project Type Bill Rates coping From Project Type to Project Template and Project and Task if i over ride at Project level it is not changing at Task level. I have Bill Rates for each Project is different How i can change without going to Task level other wise is there option bill rate should be pick from Project only not from Task. Other wise is there any option Bill rate Should not copy from Project Type To Task.

Thanks

Srini