WAP-7 - तेरे जैसा यार कहाँ , कहाँ ऐसा याराना , याद करेगी दुनियां तेरा मेरा अफसाना. - Arjun Rai

think so --
Various quotas are prescribed by the Railways from time to time. This apart,
accommodation in some trains is earmarked specifically for security
personnel, railway staff, medical teams etc., which have to be managed
effectively....
more...

Non-allotment of vacant berths earmarked for tatkal quota
During the course of printing of the final chart in ER, it was seen that all the
vacant berths, except berths earmarked for Tatkal Quota, were released for
clearing waiting lists. However, a large number of vacant berths earmarked
for Tatkal Quota were not released to the waitlisted passengers, resulting in
under-utilisation of accommodation and depriving the needy passengers of
the accommodation in the trains.
[source]
may be the answer think so