The student profile is the most important part of the admission process. Your profile will decide whether you will get the admission or not. Student profiles are evaluated based on different criteria. Your Score (GPA, entrance test scores, School grades), Resume, Statement of Purpose, Letter of recommendation, Research work (if any), work experience (if any), this is the basic method of profile evaluation.
For a bachelor's in mechanical engineering MIT, Stanford University, UCB, California Institute of Technology are some of the best universities you can choose from. The tuition fees for these universities are,
Stanford University- $55,473
California Institute of Technology- $52,506
There is a standard procedure for most profile evaluations. The admissions officer will evaluate your profile based on your academic scores, social profile, past achievements, work experience, if any. NYU is one of the best colleges in the US with its QS world ranking at 39. The average tuition fees for undergrad at NYU is 51,828 USD.
There are universities which allow you to explore several disciplines during the first year of your undergrad program
After that, you can choose to specialize in one subject
The University of Melbourne is one of them
So, if you don't want to take a gap year, you can look for these kinds of programs