Is it possible to connect multiple sources into one process ,with different type of sources (ARIBA +SAP ECC , Success factor + SAP ECC, MS-SQL + SAP ECC) ?

The short answer is yes.

You would need to set up multiple data connections and connect to each source system one by one.

Then depending on the use case, you could create the transformations in the different scopes then bring it all together in the global scope. Or setting up a data preparation data job in the global scope where you would "import" all data from the different sources via creating views.