Hey guys, I was wondering when is the last day to enrol for a uni?
You usually receive a date before your offer lapses, so make sure you make a decision and tell the uni if you accept or reject before that happens. For enrolment specifically, this will vary for each uni. You'll either receive in your offer the census date or usually you can check up the census date online via a simple Google search - e.g. search "[insert institute] principal dates for 2019" and it usually pops up somewhere.
And also if some courses in the atar profile have <5 and N/A, does that mean they gave less than 5 offers for that course? And for the N/A that no offers have been offered?
Respectively, the short answers are "probably yes" and "may not have had information given, unknown, course isn't running that year or possibly zero offers made".