In TeamSite content stored in the form of data capture record ( xml format).
In AEM content stored in the form of properties's value in JCR nodes.
Create a mapping between dcr (xml) nodes to jcr nodes/properties.
Then you can create a custom java application that can read xmls (dcrs) from TeamSite as an input and can create JCR node tree as per mapping and store content in the form of properties values in created jcr nodes in AEM
