I went to a Roman Catholic school where graduation was 100% there weren't different tracks of study either. EVERYONE had to get the same regents level diploma.
In St. Louis, most of the Catholic K-8 parish schools will not accept students who have learning disabilities, especially in those parishes with "better" schools that have waiting lists. In my neighborhood, Catholic kids with LDs went to the public schools until their LDs were resolved & they re-entered the Catholic system.
The tracking at the Catholic high school level takes place during the high school admission process, where better students apply to the top-tier high schools. There are low-tier high schools for poorly performing students, and there are a few large "all-purpose" high schools that have tracking within the schools.