UPSC

The UPSC (Union Public Services Commission) conducts dozens of exams each year for entry into central government services, combined Medical and Engineering services, Economic service and the Indian Forests services.
In addition UPSC also conducts the CDS for entry as commissioned officers into the Indian Army- Military, Navy and Air. There is no reservation for SC, ST and OBC in the UPSC conducted defense services exam-CDS and NDA tests.

However there is a fee waiver for female SC and ST candidates once selected. There are some seats reserved for NCC cadets though. Here is the list of some of the competitive exams in India with the time of their exams