Hello Mahesh, 

Yes, work experience is necessary for doing MBA in Australia. You need to have 3 years relevant work experience or 2 years relevant work experience and a GMAT Score of at least 650. 

For further details on eligibility criteria check the link: http://www.business.uwa.edu.au/mba/MBA-Full-time/admission-requirements-and-how-to-apply#ui-accordion-1-header-2

All the Best !