The fast by the TRS president in 2009 led to the Centre announcing that it would take steps for formation of separate Telangana though it had subsequently said it needed to hold further consultations on the contentious issue.
The TRS leaders and workers observed the day as 'deeksha diwas' in Hyderabad and other places.
Telangana Joint Action Committee (JAC) Chairman M Kodandaram and other leaders addressed the gathering in Hyderabad.