I am unsure about this because I also got an iPhone 6 from USA and it had a speaker malfunction and they were able to repair it without any issues.Fun Fact- I got iphone 7 from usa in 2016, the phone had some manufacturing defects and within 1 month I went to apple store in delhi and they refused to replace or repair it because its warranty was apparently covered in USA. Also if u buy apple care in usa it will work in usa only or any specific country u got it from, so my advice buy apple products from india only
Lol, maybe they didn't know it was a US phone, idk.