I am non-US citizen hoping to study in US. I have a good chance of getting admitted in one of the Ivy leagues in US. Considering that my family has no property large enough to take a hefty loan on, Can i as a student take such a large sum of money as loan, with just the promise that I will be earning a lot after I graduate and will be able to pay the fees in time?
This article gives the very good advice to simply contact one of the schools in question and ask how to apply for financial aid as an international applicant. Most Ivy League schools admit so many international students that they will have answers to any financial question you can imagine. They may even already explain the financial aid process online.
I would be surprised if a bank cared about an undergraduate major. Usually, such things are only important if it is a professional degree, like a law degree or medical degree.
The big issue is that if you are not a US citizen, a US bank would be unlikely to make an unsecured loan because you could just return to your country and renege on the loan and they would have no way to collect. Therefore, a bank in your own country might be more logical.
If you get accepted by a top Ivy school, they all have financial policies that will allow you to attend regardless of how rich or poor you are, so if you are applying to a top school (Harvard, Princeton, MIT, Stanford, Yale) and get accepted, they will fully finance your attendance. The only exception is if (A) they find out you lied about something, or (B) your parents/family are wealthy and they refuse to pay anything. As long as neither of these two things is true, all of the schools listed GUARANTEE they will provide sufficient financial aid. Princeton even has a no-loan policy, which means not only will they fund your attendance, they will do so without you having to take on any loans.