Before federation, each of the six colonies had its own constitution. These constitutions regulated, among other things, the Legislature, the Executive Government, and the Judiciary of the States. The Australian Constitution expressly guarantees the continuing existence of the States and preserves each of their constitutions. However, the States are bound by the Australian Constitution, and the constitutions of the States must be read subject to the Australian Constitution (ss 106 and 107).
In contrast to the Commonwealth Constitution, the State Constitutions are in general, simply regular pieces of legislation that are subject to amendment or repeal by the State Parliaments in the same way as other legislation. The State constitutions are the source of the State parliaments' power to make legislation and are concerned with the structure and process of the institutions of government: the legislature, executive and the judiciary.
The official versions of State Constitutions, as passed, as amended, point in time and current compilations are available on the respective states' government legislation websites.
The current compilations are:
The position of the territories is different - they do not have constitutions as such. The Northern Territory and Australian Capital Territory (ACT) were granted self-government by the Commonwealth in 1978 and 1988 respectively with the passage of Commonwealth legislation. These self-government laws are the source of the ACT and NT parliaments' law-making power and are structured similarly to the State and Commonwealth constitutions, with chapters on the functions of the Legislature, the Executive and the Judiciary. Territories can make laws for any matter as long as it is not inconsistent with a Commonwealth law made under s 51 of the Commonwealth Constitution.
Source: George Winterton (ed) State Constitutional Landmarks (Federation Press, 2006).
The Constitution of New South Wales by 
The Constitution of South Australia by 
