While I don't know for sure what
ganeshkrishnan intended, I'm going to take from the name and comment ganesh knows both countries. Perhaps what Ganesh meant is the while the population density in those Australian cities is very low, Australia has a highly urbanised population. ~11% of India's population are urbanised, 2/5 ths of australia's population is in just two cities. You hear figures for 80 or 90% of Australia's population is urbanised, but I don't have a cite.
I didn't mean the population density. I meant the density of urban vs rural spread. Australia has the world's highest urban ratio (around 96%) and extremely well connected. India is more spread out.
I think the real reason why India has a low count (for now!) is because it's a world away from China in terms of people travelling to each other while Australia is very deeply connected to Australia (students + mining export).