How to enable T9 or Predictie Text Input for Symbian

Programmatically you can set the flag while creating the resource like

flags =EAknEditorPredictiveInputMode

Or one can use the below method

IMPORT_C void SetPredictiveTextInputPermitted (TBool aPermitted)

Also make sure it is enabled in your phone by default.

You may enable it by going to the Settings application, normally in the Tools folder, select "Phone" from the list of settings, select "General". The last setting in the settings list is whether or not predictive text is on or off. (Dictionary)