Following persons are not required to file GSTR-9:
– an Input Service Distributor,
– a person paying tax under section 51 (TDS) or section 52 (TCS),
– a casual taxable person and
– a non-resident taxable person.
The person paying tax under section 52 (TCS) is required to file GSTR-9B but since, provision of section 52 is applicable from 01st October 2018 only, they are not required to file GSTR-9B for the year 2017-18.