The question is here when you start your preparation? If you are a 3rd-year student then do prepare the most important topics like micro, macro, mathematics, statistics.

on the other hand, if you are in the second year then you have enough time.

DSE entrance is quite difficult if your basic concepts are not clear. You have to make sure that your undergraduate content is on your tips.

After revision of everything try some test series of DSE, exam pattern, previous year questions, assignments.

I suggest you spend your amount on these last-minute preparation notes, test series, and assessments.

You can also refer to Sameer Sir's notes(Samikon classes). Watch some of his classes on youtube.