Permission is not granted to SP sites directly from IIS.
If you know or know the administrator of the SP site collection, ask them to give you the appropriate access to the SP site you are requesting. Otherwise, if there are no site collection administrators, go up to the SP farm administrator, ask the farm administrator to provide you with a site collection administrator for the SP website collection that you are trying to access. The team project site is under the site collection.
From there, you can give other users access to the appropriate SP resources using Site Actions> Site Permissions.
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