Is 々 commonly used and recognised by Chinese people? In Japanese the kanji 々 is used as a repetition kanji.

So instead of typing say 人人 you could type 人々.

Is this character recognized by Chinese people nowadays ?

For example instead of 谢谢 could I use 谢々.

Actually it's more of an effort to type 々 instead of the original character but I'm curious all the same.
It's not common in publications or daily writings nowadays, but all people can recognize it. It often appears in the calligraphies or on posters. The writing space of those media is precious.

And some teachers like to use it in class. 

BTW, the Chinese prefer the right one, the cursive style, in their handwriting.

The source of it: cursive 仝, the variation of 同.