Please refer to below for the list of the extension with the limitation on the characters:

.com/.net/.org/.biz/.info/.us/.name/.cc/.tv/.com/.net (3~46 characters)
.cn/.com.cn/.net.cn/.org.cn (3~46 characters)

.com.tw/org.tw/idv.tw (3~46 characters)

.hk (3~46 characters)

.eu (2~63 characters)