GSTR 9 applicability

Yes...

You have to file Annual Return i.e. FORM GSTR-9 for both FY 2017-18 and FY 2018-19.

However, if you have taken Registration after 01.04.2018 i.e. in FY 2018-19, then you have to file GSTR-9 only for FY 2018-19 and not for 2017-18.

The GST common portal has not yet enabled the option to file GSTR-9 for FY 2018-19.

thanku sir.. I have registered since 2017

Then you are required to file GSTR-9 for FY 2017-18 and FY 2018-19 as well