There are multiple definitions - click on the translation that matches your context.
Substantiv
partial
noun
In most legal contexts, the word "appeal" will be the best translation. Although if the complaint is directed at the same government agency unit that issued the decision (and not at a higher unit), then the more general term "objection" may be better.
the action of asking a higher court to review and change the decision of a lower court; a review by a higher court of a decision made by a lower court
She lost both the case and the appeal. Her final route of appeal is before the Grand Chamber of the European Court.