I’ve lived in Iran for 5 years. During those years, I experienced many interesting things. I met people with different beliefs,and I was brainwashed multiple ways. Do you guys think this would be a good essay topic? If not, could you tell me a few good ones?
I think it sounds pretty good. Your voice, ability to tell your story, and relation to the prompt would matter more, I’d wager – but that’s good to write about 
“and I was brainwashed multiple ways.”
that sounds like a tricky essay to write.