For my ECE / ISyE application, should I mail any supporting documentation to ECE / ISyE?
No, the individual departments do not expect any direct mailing from you. All necessary supporting documentation (official transcripts, degree documents, official TOEFL and GRE score reports) should be sent to GT Graduate Admissions. ETS sends your GRE score report electronically to Graduate Admissions and via paper to the individual department(s) that you designate on your GRE score report request form.