“Yes, but Harvard IS a research university, and in physics it is a research powerhouse. Please don’t misinform OP by telling him or her that Harvard physics may be lackluster in its opportunities for research.”
But it is not unusual for high school kids who say “physics or math” to end up in university wanting to do “engineering”. I personally wouldn’t go to Harvard for engineering. Not that it would be terrible, but there are better choices for engineering, which in many cases are excellent for physics and math also.
All of which might be semi-beside the point if OP doesn’t get into Harvard, other than to point out that there are other schools that she can get into which would also be very good choices (and that some of us would prefer, and some of us would not, if it were our choice).
By the way, in the original post OP says “…wondering if harvard is a real option with my mediocre GPA and test scores.” 1590 out of 1600 on the SAT, with four 800’s on subject tests does not count as anything other than “superb”.