If you are holders of X1 visas, you would be required to go to the Nanjing Municipal Public Security Bureau（PSB） and arrange for a residence permit within 30 days of entering the country. And before going to the PSB, it is necessary to firstly go to the Office of Student Affairs, IIS (your host institute at NJU) to provide proof of a valid visa. So if you arrive earlier 30 days before the registration periods, you will not be able to get help from the Office of Student Affairs at NJU on visa issues. We suggest all exchange students confirming with the Chinese consulates near your city on this issue, and putting the above-mentioned situation into consideration.