Sparschiene tickets

A seat reservation is not required.

If you want a seat reservation, buy one at the train station a day or so before you travel.

If you don't want a seat reservation, just sit in any, empty unreserved seat.

"Also- do I need reserved seats at all?
In my country it is mandatory.
So I am confused."

It is different in each country in Europe, and different on different routes in the same country. Sometimes reservations are required (in that case, they're sold with the ticket; only rail pass holders have to buy a separate reservation). Sometimes they're optional, and sometimes they're not available. Furthermore, when they are optional, sometimes they are a very good idea, and other times they are usually unnecessary.

So, you need to check for each route; there is no simple rule that applies in every case.

I just tried to make a reservation for the date and route you mentioned, and it was no problem.

Go to the ÖBB ticket shop https://tickets.oebb.at/de/ticket (the English version seems not to work at the moment), enter your train (date, time, route), select it from the list as if you wanted to buy a ticket, select the option that you have already a ticket, which will lead you to the seat reservation page.

As said before, there is no general rule for seat reservations. There are certain trains where it is mandatory. For other trains there may be a note recommending a seat reservation in the online train schedule if there is a considerable number of seats taken already.

I always reserve a seat because it is more comfortable. You need not to walk along the train with your luggage searching for an empty seat, and I want to sit at a table where I can put my stuff (food, beverages, newspapers, laptop).

Hey! Thanks!
But.... now that I have already bought it without any reservation- is it possible to pay the extra (6Euros I think) and get the seats booked?
The English one doesn't allow reservation I think. I booked Vienna - Salzburg too yday and the same thing happened. However since I don't know any German at all can't use the german version 😔
Please guide me
Thanks a lot

In the Vienna train stations ( Hauptbahnhof , Westbahnhof , Praterstern , Wien - Mitte ) there are Oebb ticket offices ( Reiseburo ) , you can purchase reservations there . I have traveled on Railjets a number of times and always reserve my seats to avoid inconvenience , the cost is of no consequence .

Go to the ÖBB ticket shop https://tickets.oebb.at/de/ticket (the English version seems not to work at the moment),

Sorry, this was not correct. The ÖBB page switches automatically to the language locale of your browser, no matter what language you choose on their page. Now I tried this on an English PC and it works: https://tickets.oebb.at/en/ticket

Just pretend to buy a ticket for your train, and when you get the price list, choose "More Options" and select that you have a ticket already. Further down you will get then upgrade options and the seat reservation menu.

I just read your update , wmt1 . This is very helpful and gracious of you !

Thanks so much
Truly appreciate all the help