\documentclass[a4paper,10pt]{article}
\usepackage{myXsim}

\author{Benjamin Bertrand}
\title{Information chiffrée 1 - Exercices}
\date{Septembre 2021}

\DeclareExerciseCollection[step=3]{banque}
\xsimsetup{
    collect,
    exercise/the-counter=3
}

\begin{document}

\input{exercises.tex}

%\setcounter{exercise}{2}
\printcollection{banque}
\vfill
\printcollection{banque}
\vfill

\end{document}