Case by case
The most common pronunciation is あい (ai), which is the training pronunciation
For example, the Japanese female golfer Aoi Miyazato (みやざとあい )
But you can also change it by typing らん(ran) and あお(ao) on the computer
らん is the phonetic pronunciation, usually only placed in front, such as 蓝香 (らんか) =ranka). Of course, there are exceptions
あお is a special case, usually Ao (あお), which is rarely used by Japanese people
Please refer to it