Page "Bundesrat of Germany" Paragraph 30

The Reichsrat of the Weimar Republic had considerably less influence, since it could only veto bills and even then be overruled by the Reichstag.

However, overruling the Reichsrat needed a majority of two-thirds in the Reichstag splintered into many parties.

So in most cases a bill vetoed by the Reichsrat effectively died because there were not enough votes in the Reichstag to overrule the veto.