"Railways have started local train services for its own employees who are involved in the operation of Shramik and passenger trains. The National Railway Mazdoor Union (NRMU) has, however, asked railway authorities to increase local train services in order to maintain social distancing."
NRMU's demand proves that starting locals in phases is simply not worth. 6 services are not sufficient for only railway employees when office/work occupancy is not 100% yet. If you want to start locals, start all services right from day 1. Still no one can guarantee that social distancing will be followed.