Which Font should be imported in order that  Mandarin chanracters are supported 

I do not believe that Mandarin is supported at this time. However, you can type your characters into a program such as inkscape or illustrator, convert them to outlines, and then save them as an SVG. The SVG can then be imported into videoscribe.

related link:
http://help.videoscribe.co/support/solutions/articles/1000033724-write-with-non-western-text-characters

another instructions about making a text SVG:
http://help.videoscribe.co/support/discussions/topics/11000005258

-Mike (videoscribe user)