>> You must meet the following prerequisites before enabling territory management: >> Your organization must be using customizable forecasting in order to enable territory management. If you do not know whether you have customizable forecasting, see Do I Have Customizable Forecasting?. Follow the steps in the Deploying Territory Management Guide to prepare your organization for territory management.
However, please find the below mentioned link, which will provide you more information.
>> You must meet the following prerequisites before enabling territory management:
>> Your organization must be using customizable forecasting in order to enable territory management. If you do not know whether you have customizable forecasting, see Do I Have Customizable Forecasting?.
Follow the steps in the Deploying Territory Management Guide to prepare your organization for territory management.
However, please find the below mentioned link, which will provide you more information.
>> https://help.salesforce.com/HTViewHelpDoc?id=territories_enable.htm&language=en_US
Regards
Pramod