ascension - How to find maximum and minimum right acsension and declination based on the telescope's location?

In the Southern hemisphere, the maximum declination you can see is
90-L where L is your latitude. The minimum is -90, since you can see
the south celestial pole.

As the earth rotates and revolves, you can see any right ascension
within those declinations.

The only exception is that you ordinarily can't see stars that are too
close to the Sun. However, the Sun moves enough between October and
March that all right ascensions will be visible at night sometime
between October and March.