Degree

B.Tech/BE through lateral entry (direct second year entry) is the most sought after course after diploma, you can appear for LEET examination and opt for the desired engineering branch. The duration of the course is 3 years as you will enter second year directly.

The colleges which offer a course in meteorology in Tamil Nadu are St. Peter's Engineering College, Chennai, Tamil Nadu and Agro Climate Research Centre, Coimbatore. Other than that there are many other colleges in India where you can pursue meteorology. You can search online and navigate to a college of your choice.

You can pursue but you need to justify the gap in your studies. Before taking admission, I would suggest you to have a word in the institute and explain them about the whole scenario.
AAIP is a certificate course.
For details refer: https://www.shiksha.com/animation/2d-3d-animation/course/arena-animation-international-program-aaip-animation-arena-animation-acedemy-chandigarh-163399

Hello Junaid,
You are advised to read the PR rules and protocols on the Australia immigration website, check the procedures and how you can apply. I hope you are aware of getting a job first and working in Australia before you could apply for a PR. This is the official link below:
http://www.australia.gov.au/information-and-services/immigration-and-visas