请教皮匠老师和863211老师:在哪里面谈不上?

My sister's priority date is current, I am preparing her application now. She lives in China, but her son is studying in UK (the last year for college), then will go back to China next summer.

My question is if interview is scheduled in a few months, is it depending on county they currently live or is it in China regarding less where you live now ?

Thanks very much!!!