Mechanical Engineering

No college or branch change is applicable after the 1st-year. There is no provision to change in college in the 3rd-year across India.

The first and basic qualification required for a Ph.D course is that you must have completed your Master's degree course.
To apply for Ph.D, you can either directly apply to the professors of
different universities sending them your resume, Statement of purpose and your research papers. Or you can appear for UGC-NET examination
and then sending your NET scores to the professors under whom you want to undergo your Ph.D course.

If you have a 3-year's Bachelor's degree then Australia is better because Canada does not accept 3-years Bachelors.

Hi Ashish,
If you meet the entry requirements, then yes you can apply. But, it is suggested you apply for advanced diploma or even Bachelor's degree since you already completed your 12th. Your application will be rejected if you are applying for more or less for the same level of program.

Hello Swapnil,
There would be more than 100 institutes which may fit the bill. But it would be outside the scope here. Admissions depend to a large extent on your record of academics. Hence I would advise you to approach specialised agency dealing with sending students to Germany or US for guidance.

No, first you need to complete Bachelor's degree then only you can do MBA.

As you are in 12th, all you need is to maintain 75% or more than 75% in CBSE boards exam and need to clear JEE Mains exam with a good score. Just qualifying JEE Mains with the minimum cutoff doesn't make a sense. If you want mechanical with specialization in automobile you need atleast 180+ in Mains.
So don't worry, just focus on your boards and JEE Mains preparation.
All the best!!