1.Taxpayer whose Turnover is Below 2Crore can file GSTR 9 , without any CA certification.
2. Taxpayer whose turnover exceeding 2Crore is liable to get their account Audited by CA (Section 35(5)) shall submit a copy of the audited annual accounts, the reconciliation statement (GSTR9C) under sub-section (2) of section 44 , with GSTR 9.
So in first condition the Taxpayer himself can file the GSTR 9