If your Registration has been cancelled on or before 30th September 2018, then as per Notification No. 58/2018, CT dated 26.10.2018, you have to file Final Return ( Section 45 of CGST Act 2017 ) in FORM GSTR 10 within 31st December 2018.
You are not required to file Annual Return u/s 44 of CGST Act 2017 in Form GSTR 9.