-Photocopy is enough.
小孩11岁,需要打指纹,面试,宣誓吗?
-It is possible to be interviewed or/and collected biometrics (determined by the IO, case by case), but no oath will be taken. Read the N-600 Instructions and this link:
https://www.uscis.gov/forms/n-600-application-certificate-citizenship-frequently-asked-questions
我们两个月后会回国很长时间,如果要面试什么的估计来不及。不知道现在n600批下来大概要多长时间?
-Why won't you do it after you come back? It is not urgent to get this certificate, anyway.