Hi Khushbu
If you want to work in Australia you will need to research the different VISA laws etc. Trying to come "onsite" is a challenge. SAP job demand goes through cycles and sometimes it is difficult to find a position. You might want to look at the large consultancies and see if there is an opportunity for onsite work as part of the project (more than likely make sponsorship easier).
The difficult challenge - most times development work is sent offshore (not all places of course). The work kept in Australia is either they cannot outsource it (federal government and so you need to be an Australian citizen) or it will be more senior staff (10+ years experience). It doesn't mean the work isn't available but you might be competing with other established professionals.
Regards
Colleen