Can an Australian NRI get exemption on capital gains?

I assume that you are a non-resident as per Indian tax law. Liquid funds typically invest in a portfolio of money market and short-term debt securities, and since investment in equity shares of domestic listed companies is less than 35% of its total portfolio, they do not meet the criteria of being an equity-oriented fund. For units of mutual funds other than equity-oriented funds, the period of holding to qualify as a long-term capital asset is three years. The period of holding as per your facts exceeds three years. For debt-mutual funds, TDS on long-term capital gains for NRIs is 10% without indexation benefit (plus applicable surcharge and cess) and so would the final tax, too.