What sort of GPA are top tier colleges like NYU, UVA, or Duke looking for?

Out of the 3 colleges, you asked GPA data on NYU is the most lenient with the avg. unweighted class GPA at 3.7. The other two have near-perfect GPA averages.

NYU - Avg UWGPA 3.70 (from NYU website for Class of 24')

Duke - Avg UWGPA 3.94 (from published sources)

UVA - Avg UWGPA 3.95+/- (from 2019/20 Common Data Set)

Percent who had GPA of 4.0: 91.20%

Percent who had GPA between 3.75 and 3.99: 5.30%

To answer your question on whether colleges look at current GPA versus overall GPA, they look at an overall GPA which encompasses 9-12th grades. Some colleges like Stanford mostly care about your 10th/11th grades and give you a forgiving "mulligan" for your 9th-grade performance if it was underwhelming. While all colleges take in account your course rigor for 12th grade and your mid-year and final grades, they mostly care about your 1/2 year report because it is available in most cases for RD applications. If you have weaker grades, it's sometimes best not to apply early decision or EA because having an extra semester of grades can help you if you are trying to prop them up a little.

My recommendations are to pick more schools like NYU that reach schools with lower GPA standards versus UVA and DUKE which are hard reaches even for people with straight As. Although UVA has higher acceptance rates (33% instate) than Duke and NYU, UVA is really hard to get into if you are applying out of state (15%) and 90% of admits have a 4.0 Unweighted GPA. To get your grades up, you need to take more classes and get better grades in them. Also, consider taking 2 college courses this summer if your HS is not offering classes over the summer. Any additional classes you can get As in will help your narrative. Since you are lacking in unweighted GPA, I would say that it's better to sign up for 6-8 unweighted classes for 12th grade where you can get As versus taking a bunch of AP classes where you might settle for Bs. You are trying to get as close to a 4.0 for the rest of your HS career and taking a bunch of super hard classes will not help you.

Also, to help prop up your potential as a college student, you should seriously consider taking either the SAT or ACT with the intent of submitting a 1500+ or 34+ score. Standardized tests are not required but in your case, they can help you if you score in the 98-99%+ percentile range since your UWGPA doesn't reflect that you are a top applicant for consideration to elite colleges. The other thing that can help is if you have a legitimate spike such as being a recruitable varsity athlete or having some state/national level talent in music, art, or leadership position. ECS is very important in differentiating excellent candidates from exceptional candidates.

Lastly, I do not know what your socioeconomic status is but many underachieving HS students who have potential but have made some missteps in their academic career have taken a gap year right after HS to attend a PG program at a boarding school to get another 2 full semesters of HS grades added to their transcript. There is no negative shade that is thrown on someone that wants to better themselves and be a more competitive applicant when they apply to the colleges they really want to attend versus settling for schools that will have them. Therefore, if you are not in a rush, you should investigate boarding schools that offer a PG (Post Graduate Program). Most of the best schools in the country offer a PG program and students who take this route have a much better chance of getting into the college of their choice from a place like Choate, Hotchkiss, or one of the 2 Phillips Academies. If money is a factor, they all have excellent financial aid. If you do not qualify for aid or admission, you can still refrain from applying to the college of your choice and repeating 12th grade locally or attending a community college and transferring as well.

I hope this was helpful. Remember no one cares how you got into college but remembers where you graduate from. So if it takes more time who cares.

Top schools usually look for 3.7 as the lowest 4.0 or higher. Duke requires a 3.94, NYU requires a 3.69, and University of Virginia is a 4.22 which means that choice is not an option for you. Note that the GPA is NOT the only thing schools look at, extracurricular activities they look at as well. If your school offers college classes take a semester of one easy class. Hope this was somewhat helpful.