Depending upon how much financial aid you need, there may be no safeties in the US. There are of course lots of liberal arts colleges where admissions is very likely or close to certain, but affordability might not be as certain. I do think that there are many LACs in the US where your son’s chances are quite good including affordability. As reaches I wonder about Amherst College, Williams College, and Bowdoin College. All are highly ranked and very good but would be reaches.
There are small “primarily undergraduate” universities in Canada which would be both safeties for admissions and probably only about half of the cost of universities and colleges in the US. We looked at several in the eastern part of Canada (we live in the northeast of the US). Acadia, Bishop’s, and Mount Allison are three very good options. Acadia University has the advantage that it would be easier to fly into from India (presumably via Europe) since it is a reasonable taxi ride from the Halifax airport. It is also very good for biology. None of these schools are well known outside of eastern Canada, but the education quality is excellent and there are very good research opportunities available. All have rolling admissions, which given your son’s excellent stats should bring an acceptance quite quickly.
Regarding the University of Vermont, given your son’s excellent stats I think that admissions is close to certain and a presidential merit scholarship is very likely. Whether this would be sufficient to make it affordable is hard to say. The NPC for UVM does predict merit (or did a few years ago) and was accurate in our case.