Once the war started, the Romans plundered and persecuted the Christians as well as the Jews wherever they came through.
Considering the truth that the Book of Revelation was revealed by God and that the prophet John correctly wrote down the truths he was shown, we can see that the time related information in the book (internal to the book) is the most important criteria for dating the writing of the book.
Other than that, the readers have the privilege to consider the matter and to come to their own conclusions concerning this topic.
I have listed only some external sources, they are repeatedly used by representatives of both positions as a support for their respective interpretations.
Irenaeus mentioned in another one of his works concerning the number of the name of the antichrist that this number is found in all ancient and approved or recognized copies/writings.
This mention of "ancient copies" is interesting because Domitian's reign ended only shortly before Irenaeus' own time and if the book were written in about 95/96 AD, there would hardly have been any "ancient" copies of the book in his day.