Where the requirement actually comes from
Two layers apply. HEC sets national policy for PhD programmes, including expectations around publication in recognised journals. Individual universities then implement it, and many add requirements of their own — a minimum category, a specific number of papers, or a rule about which author position counts.
This is the single most important thing to understand: your university's rules bind you, and they can be stricter than the national policy. A requirement someone quotes from HEC policy may not be the requirement you actually face.
Get your own institution's current PhD regulations in writing, from your graduate office rather than from a colleague. Policies change between cohorts, and the version that applies is usually the one in force when you enrolled — which may not be the one on the website today.
Your university's rules bind you, and they are often stricter than national policy. Get them in writing from your graduate office.
What the rules usually specify
A number of publications, sometimes distinguishing between accepted and published. Acceptance letters and publication dates are not interchangeable in most regulations, and a paper accepted but not yet published may not count.
A journal standard, normally expressed as HJRS recognition and often a minimum category. Since categories change between cycles, the status at the time of publication is what will be assessed.
Author position — many regulations require the student to be first author, and some require the supervisor to be a co-author. Conference papers and book chapters are frequently excluded, and a thesis chapter published as a paper is usually acceptable but not always.
Planning around the timeline
This is where students lose years. Peer review takes months, and a paper submitted in your final semester will very often not be published in time to satisfy a requirement for that submission deadline.
Work backwards from the intended defence. If a paper must be published, allow for review, revision and the production queue — and note that acceptance and publication can be months apart at journals with a backlog.
Choose journals where you have verified both the current HJRS category and the realistic turnaround. A journal that is recognised but takes eighteen months to publish may not be usable for a deadline, and the fastest journals are often the ones worth checking most carefully.
Verify the category at submission and again at publication, and keep dated evidence of both. If a journal loses recognition between those points, the record of what was true when you submitted is the only thing you will have.