C visa is usually meant for the alien who is passing through the United States to another country. To Obtain C visa, an alien is required to demonstrate that he or she will be in immediate and continuous transit through the United States.
Generally, C visa is given to individuals, who are merely passing through the United States; certain aliens who are in transit to the United Nations headquarters district; certain foreign government officials, members of immediate family, attendants, servants, or personal employees, in transit, passing through the United States to another country; and aliens from certain countries that have agreements with transportation lines may transit through the United States without fulfilling the documentary requirements. Usually, this is called TWOV-transit without visa. Aliens who are admitted to the United States As TWOV, Entry must be made at a designated international airport, and a person’s stay in the US is limited to eight hours.
An alien to qualify for C visa, must meet all of the standard nonimmigrant requirements, and must prove that his or her only purpose in coming to the US is to pass through in transit; he or she has a ticket or other means to reach their final destination; he or she has sufficient funds to reach their final destination; and he or she has permission to enter the country in which their final destination is located, if such permission is needed. The maximum length one may be granted to stay in the United States under C-visa is 29 days.
It is important to remember that entry on C visa into the United on a transit visa is not considered official entry into the US. C visa holders cannot change status in the US, except to that of an employee or official of a foreign government or international organization. Aliens in transit cannot work, and they cannot seek any extensions of stay