I need to get an advice to get a group visa. Ivy

We are a group of 6 planning a 8 day tour to china through a Chinese tour company in June. In our group there are 4 Australian passport holders & 2 Sri Lankan passport holders, these two are permanent citizens of Australia. Please advise us whether we are allowed to get a group entry permit as we all are going the trip at the same time with the same tour group. Plz advise the total cost involved & the when to apply for it.