What are my chances of getting into Ivy League (particularly brown) and other top schools

By the time I apply my senior year, I’ll have about a 3.86 unweighted gpa my sophomore and half my freshman year I had very debilitating health problems which caused me to miss nearly 50 days of school throughout the year, which is the cause for the low gap, which my counselor is planning to explain in my application.

For classes,

Freshman year:
Band
English 9 H
AP human geography
French 2 (no honors offered at my school)
Band
Art
Alg 1
Biology

Sophomore:
Band
Chemistry H
AP Euro
Geometry H
English 10 H
French 3

Junior
Band
AP Biology
AP American Gov
Alg 2 H
AP micro and macro econ
AP French
British Literature H

Senior (planned classes)
Band
APUSH
AP French
Chinese 1
AP English (Lit and Lang)
Pre calc H
AP Physics
AP Psych

Test Scores:
ACT: 36
(Projected) SAT: 1580
SAT subject: French 800, Biology 800 (planning on taking US history and Math 2 also)

Extracurriculares:
Policy Debate
Writing tutoring for elementary school kids (volunteer)
Democrats club
Students for Diversity

Summer activities
Attended Interlochen for 6 years (one of the most prestigious fine arts summer programs in the country) for visual arts
Volunteering at library &a summer tutoring & art lessons

Awards:
National honors society
Multiple national gold level awards for Scholastic art and writing

Ethnicity:
Latina

Based on this, do I have chances in top colleges (especially brown) and what should I do to improve my chances within the next year?

“do I have chances in top colleges (especially brown)”

It is very hard to say. However, I think that you probably do have a chance. 3.86 unweighted is pretty good for someone who has dealt with significant health problems. Definitely have match and safety schools as well, and check the NPC.

Are your health problems effectively dealt with currently?