座席指定は任意だと思います

reiseauskunft.bahn.de
EC 86 Eurocity Richtung: München Hbf
Fahrradmitnahme reservierungspflichtig , Fahrradmitnahme begrenzt möglich , Bordrestaurant
Betreiber: DB Fernverkehr AG

予約が必要なのは、人間様ではなく、お自転車様です。

www.lefrecce.it
Db-oebb Eurocity 86 - da Venezia S. Lucia a Muenchen Hbf
なにも記載なし

www.obb-italia.com
Eurocity ÖBB
Giornaliero e diretto dall’Italia verso il Tirolo e la Germania.

Informazioni sulla prenotazione
In Italia viaggiate con il biglietto "Offerta Speciale" a partire da € 9,-.
Con il biglietto "Sparschiene" viaggiate dall’Italia verso l’Austria a partire da € 29,-.
I prezzi di tutti i collegamenti in Italia e verso l’Austria sono sempre disponibili nella sezione ÖBB Ticketshop.
これが決定打でしょう。
Non è obbligatoria la prenotazione del posto.やはり、座席予約は任意です。
E’ possibile prenotare il posto a sedere in 1° o 2° classe a partire da soli € 3,-.国により若干差がありますが。

ww.bahn.de
Nur Sitzplatz (kein Ticket)
Venezia Santa Lucia ab 13:35 EC 86
München Hbf an 20:25　11
Zur Reservierung

Reservierungswünsche
Bitte geben Sie Ihre Sitzplatzwünsche an
1 Sitzplatz 4,00 EUR 1 Erwachsener, 2. Klasse
1 Sitzplatz 5,30 EUR 1 Erwachsener, 1. Klasse

FS側からのオンラインでの座席指定だけは昨年夏から不可になりました。

tickets.oebb.at
やはり、少しだけ安いのです。
Nur Sitzplatz (kein Ticket)€ 3,00 in den Warenkorb

英国鉄さんに登場願えば、
www.seat61.com
Munich & Innsbruck to Italy via the Brenner Pass...
Travel tips...

Seat reservation is optional on these trains...

Reserving a seat costs a few euros extra on top of the fare (although the German Railways site now includes a free reservation if you go 1st class). If you choose not to reserve a seat you simply sit anywhere you like in any unreserved seat. A small tag above each seat shows whether or not that seat is reserved. Reserving a seat for a long journey is a good idea, although I probably wouldn't bother if travelling solo mid-week in February. I certainly would reserve a seat if travelling on a busy Friday or Sunday afternoon or if travelling as a small group of 4, 5 or 6 people who want to be sure of seats together, or travelling at busy times such as Easter, Christmas or the summer holidays.

If you've already bought your ticket, but now want a reserved seat, you can make a seat reservation separately for a few euros at either the German Railways site www.bahn.de for journeys to or from Munich (look for the Seat only (no ticket) box right at the bottom of the page) or the Austrian Railways site www.oebb.at (select the train, click More services under the fares section then click Ticket already exists).

おまけ。


Which side of the train has the best views?

It makes relatively little difference, but in the open-plan cars the best views are arguably on the right hand side of the train going south, left hand side going north. as the valley is mostly on that side as is the little church at Jodok. You can sit where you like, but if you choose to reserve a seat you cannot specify a side as the reservation system doesn't know which way round the carriage will be.