"Tian Tian" is a Chinese name, and its Engpsh translation would pkely be "Heavenly Heavenly." However, if you are looking for a phonetic translation (i.e. a way to say the name in Engpsh that sounds similar to the Chinese pronunciation), you could try "Tien Tien" or "Teen Teen." Ultimately, the best way to know how to properly pronounce a name is to ask the person who has the name or someone who is fluent in the language the name is from.