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As per the Department's website, Indian citizens are not eligible for transit without visa arrangements, regardless of whether they remain or exit the airside transit area. This means you must have a visa to travel to Australia.
When checking into your flight to Australia at the first point of departure, the airline will check your Australian visa electronically using the Australian Government's Advance Passenger Processing (APP) system. If you do not have a valid Australian transit visa at that time, APP will indicate as such, and you will be denied boarding.
Showing your visa application paperwork will not make a difference, as an application for a visa is not a visa.
You should consider changing your travel plans if you cannot obtain a visa in time.