USA

Hi there, you should not study a Bachelors degree anywhere abroad being an Indian national given the present exchange rate of our currency. Please note it will cost you a minimum of INR 20 Lakhs per annum. In Australia it is quite extra. I have studied in Australia myself and I did my Bachelors too. I have lived in two major cities - Sydney & Melbourne. Unless you have at least INR 1 crore disposable liquid asset just for your Bachelors degree, you must not seek to study a Bachelors degree abroad.
Green Card in Australia is Permanent Residency (PR). To achieve this one must have a minimum of 5 years of post-graduate (after Bachelors degree) progressive work experience as a result of which the person must be eligible for a skilled occupation and/or an employer's nominated sponsorship. Usually after 2 yrs of study in Australia one is eligible to apply for a Post-Study Work permit (PSW) with which one can stay in Australia and look for employment. Should you be lucky enough to win over an employment offer against an Australian citizen (who will be preferred), then since that time it shall take 5+ years for a PR followed by a citizenship. Hope this helps. Thanks!