Gst on rcm

Dear All

Small confusion

During Last FY we suppose to pay GST on RCM,we paid upto oct18,We thought RCM is not applicable to pay.we left it from Oct-17 onwards.

During the Audit we realised that RCM is applicable on Specific Services.Now can anybody give your openion if we pay GST ON RCM now for FY 2017-18 will we be able to take ITC or Not.

Please note September-18 GSTR-3B return filed already.Now Annual return date extended upto 31-03-2019.

Please advise.

Reagrds

Balaji.S