Gst reverse charges

I am working for a private limited company working for development sector, wherein 350 people work. More than 200 people are on the payroll of the company and rest are working as retainers. The said retainers work for 6 days in a week i.e. Monday- Saturday from 10 AM to 6 PM. We issue a retainership/ consultancy contract letter to them. We deduct 10% TDS from the gross amt from the retainers. Also, would like to inform that the tenure of the retainers is very short as the attrition rate is very high. Now after the GST implementation, kindly confirm the impact of reverse charges of above fees is applicable or not.