Hello,
Many successful applicants to MBA programs intend to use the MBA to
change career focus. The key to any career-change MBA application is making a clear and convincing case for why you are making the change. It’s also important to give the adcom confidence that you will be employable in your new chosen role.
That said, a shift into finance is challenging because so many people want to do it. Whether or not this is a feasible case for you to make in your application will depend on the particulars of your situation: how you convince the adcom you are making an informed decision; what valuable perspective, skills, experience, etc. you’ll bring to the new industry/role; how you can successfully position yourself for an internship and post-MBA job in finance, etc.
I believe that if you get admitted to a program strong in finance and you are smart about how you pursue opportunities and use resources, you would be able to find a job in finance. It's getting admitted to such a program and making the case for your goals that will be the immediate, and perhaps bigger, challenge.