Are thee available mock exams for the middleware track that we can attempt, prior to going for the professional exam?
There are no mock exams as such, but Preliminary Exams should help you.
Preliminary Exams are hands-on exams that test foundational skills with technology. Passing a Preliminary Exam means someone has shown they are on the road towards production-level proficiency within a specific technology.
You can find more details on the Preliminary Exam at https://www.redhat.com/en/services/training-and-certification/preliminary-exams.
I hope this information helps you. Happy learning!