Masters

You need a degree in order to pursue Masters in any stream as Diploma isn't a degree. So, you aren't eligible to do apply for any Masters degree.

Please mention the course name that you wish to pursue for better understanding.

There are many universities that you can apply for. Some of them are like Engineering Institute of Technology, the University of Sydney, University of Southern Queensland, Australian National University, UOA. All these universities offer one or more than one Masters Courses in agricultural engineering.

Yes, you can apply for this, but before this appear for GMAT Exam and passed it.

Hello Abhishek,
To get PR in any country is mostly political decision. Though most countries, particularly Western European & Nordic do offer this to the people having skills. I feel both countries are good in this regard and it's difficult to differentiate as to which one is better than the other. I am attaching a link that will give you all the required information about PR in Switzerland. You can find similar link for Austria also. https://www.expatica.com/ch/moving/citizenship/swiss-citizenship-getting-a-swiss-passport-or-swiss-permanent-residency-107630/#SwissPassports
Best wishes.