ISSO 的答复，看不懂最后的意思

In my discussions with xxx about an H1B for you I learned that this is
a medical research job but your degree is not in the medical field. To
get an H1B you must have a degree in the field of work. A J-1 will not
bring this scrutiny,

but you will be subject to a 2 year home residency
requirement which will prevent you from getting an employment visa or
permanent residence

是说来美国后两年可以开始申请J1，还是说J1几年后必须回国两年