In your case, you should directly come to Vietnam Embassy in Overseas if you can not contact Vietnam Immigration Department.

Kindly regards,
Bella Bui

You’re always welcome to our country. Nothing is illegal when you want to work in my country. You can do anything you want providing that your activities are not involved in law.

Kindly regards,
Bella Bui

In your case, you should directly contact Vietnam Embassy in the country you are living. They will check your information and condition to issue needed document.

Kindly regards,
Bella Bui

You can directly come to Vietnam Embassy in Bangkok to request visa by yourself. At there, Embassy Officers will check your information and issue visa to you.

Kindly regards,
Bella Bui

Visa 3 months is maximum at the moment. Firstly, you should apply visa 3 months and then, you can get extension for 1 or 3 months more while in the country.

Kindly regards,
Bella Bui

4×6 is not much required as photos size in each country in the world is different. You can use passport-sized photos or popular size in your country.

Kindly regards,
Bella Bui

If you are out of Vietnam now, you should renew your visa before entering Vietnam. You can come to Vietnam Embassy in Overseas to stamp your visa if you across the border.

Kindly regards,
Bella Bui

You can enter Vietnam if your visa is still valid on this date. You can continue extending your visa while in Vietnam. However,you should renew visa 3 months if you stay longer 1 month as renewal is easier than extension. And also, the charge is cheaper.

Kindly regards,
Bella Bui

Extension for 1 month is minimum at the present. No regulation provides extension for a few day in Vietnam.

Kindly regards,
Bella Bui

Visa 6 months is no longer issued. You just can get visa 3 months as maximum. In case, you want to stay in Vietnam longer 3 months, you can get extension for 1 or 3 months.

Kindly regards,
Bella Bui