Are the annulment laws mentioned is the site below applicable all over United States?
The page at the bottom mentions "An action for an annulment must be started by a certain time. The time limit depends on the type of marriage. The shortest time to start an annulment is 4 years after the marriage". What does this mean? Can one not request for annulment till 4 yrs after marriage?
There are 50 different state annulment laws in the US, many very different from another. Your question cannot be answered as posted. If you are seeking an annulment, and very few people in Georgia qualify under Georgia's narrow grounds, you (1) need a lawyer and (2) if you want an answer here need to say what state everyone lives in, why you seek annulment, etc. Otherwise no one can answer you.
Annulment is based typically based on fraud or on a marriage that is void able for instance where one party is still married to a prior. You should contact an attorney in your area and give him or her the specifics of your circumstances to see if you can meet these criteria. Good luck.
Mr. Ashman is correct. Domestic relations laws are, with limited exception, a matter of state law. As such, the laws governing an annulment will depend on where the petition is filed. The laws regarding annulments are generally very specific with regard to when you can get one. I would strongly suggest speaking with an attorney if you are considering filing for one.
As for your other questions, it seems the language you quoted indicates that an annulment in that jurisdiction must be filed within four (4) years of the date of marriage. It is likely that it would bar an annulment filed after that time. Good Luck!