There is a prerequisite before an applicant can become an Australian citizen.
An only permanent resident is allowed to apply for the Australian citizenship test
Anyone who holds other visas like student visa, working visa which requires an English proficiency certificate is not considered a permanent resident of Australia.
An applicant should be a permanent resident who holds a permanent residency visa at least one year and has stayed in Australia for 4 years in order to be eligible to apply for the Australian citizenship test.

زایرا الیوا، مایکل ادواردز و آمنه خوجائوا در یک مراسم اعطای شهروندی شورای شهر وانیرو در پرت. Source: AAP
How long does it take to process
Damien Kilner from the Family and Citizenship Program, Department of Home Affairs says that it could take 14 months.
Citizenship test
In regard to the Australian citizenship test, applicants are expected to use the Australian citizenship resources especially the ‘Australian Citizenship – Our Common Bond’ in order to have knowledge about Australia, understand Australian democratic belief, its government, and its laws, so applicants are confident that they can sit a computer test and hopefully they would pass the test which bases on this resource.
Most of the applicants who sat the Australian citizenship test pass their mark up to 75% and it only takes half an hour to do the computer test. If the applicant failed the test, he or she can sit the test again on that day if it is possible to do so, or they can rearrange to sit the test later when they are ready without having to pay again.

Source: AAP
Citizenship ceremony
After the Australian government has approved that an applicant passed the Australian citizenship test, that person will receive an invitation letter from the local government to attend an Australian citizenship ceremony but remember to bring along your personal identification like driver license or passport because council staff will check if you are the correct applicant.
“There’s also a ‘welcome to the nation’ or ‘welcome to country’, and the minister’s message is read, the anthem is played, and then there is the pledge made by those that are attending,” says Kilner.
After that, either mayor, lord mayor or counselor will be the one who calls all to be an Australian citizen to receive their Australian citizenship certificate and to have a chance to take a photo at that moment or later on.

An Australian citizenship recipient poses for a photo after a citizenship ceremony on Australia Day in Brisbane. Source: AAP
The citizenship pledge
There are two different versions of pledges: with god or without god which local council will provide on the day the applicant attending the Australian citizenship ceremony. This is the final stage and also a signal to pledge loyalty to Australia and accept the responsibilities and privileges of Australian citizenship.
Last but not least, the Australian Electoral Commission (AEC) form will also be presented to all new Australian citizens to fill out and leave it to council staff. That means that whenever there is an election whether it is local, state or federal, every Australian age 18 years old and over must vote or they will be fined unless they have a very good reason not to, as the Australian voting system is compulsory.

Prime Minister Scott Morrison with newly sworn citizens at an Australia Day Citizenship Ceremony and Flag Raising event in Canberra,January 26, 2019. Source: AAP
At the end of the ceremony, there will also be a chance to take a photo with a councillor or having a snack before leaving if you want to.