Indian Railways — clarification against online reservation

Dear sir,

I have traveled on 30.12.17 from vijayawada to secunderabad by train no.12795 vide pnr : [protected]. I have some doubts about online reservation.

When ever tried to booking online reservation, that time showing online reservation status is general waiting is 18 and tatkal waiting is 8 (It means train is full), then i have booked tatkal ticket, that is confirmed after chart prepared my seat no. D9 / 37.

But when i was traveled, i have surprised, that train is many seats are reservation vacant. Let me know, why it is happening showing above status while booking?

Please clarify the above situation, if give the clarification its very highly appreciable.

Thanking you,

Yours faithfully,

B. Murali mohan rao
Contact no.[protected]

Ref: train no.12795, dated 30.12.17
Pnr no.[protected]
Seat confirmation no. D9/37