Para buscar um objeto de esquema de categoria global a partir do repositório, utilize RAMSession.getAllCategorySchemas() ou RAMSession.getCategorySchema(String).
//Fetch Category Schema by Name
RAMCategorySchema categorySchema = session.getCategorySchema("My Category Schema");
//Fetch Category Schema By URI
categorySchema = session.getCategorySchemaByURI(
"http://ramsrvr.example.com:8080/com.ibm.ram.repository.web/classif/mynewcategoryschema.xmi#/");
//Fetch All Category Schemas
RAMCategorySchema[] schemas = session.getAllCategorySchemas();