Q:

How can I know and contact pa auk's people who living inside this site? 

I want to contact them about tipitaka-translation, meditation, asking, and answering.  
How can I do? 

A:

I don't know. 
If you removed "inside this site" and just asked, "How can I contact pa auk's people?",  that might be an appropriate question to ask the main site. 
Have you tried pages of contact information, for example

http://www.paaukforestmonastery.org/contact.htm
http://www.visuddha-m-c.com/vmc%20sg/contact.html

Asking questions to identify people on the site (e.g. "How many people here are Theravada?")  is one of the few types of question that's defined as off-topic ("Polling questions"), so if you do post on the main site (and I guess that more people will see the question if it's on the main site, some people won't even notice that you posted on Meta), try to keep the question impersonal: i.e. "How can I contact any Pa Auk people who might help me" and not just "How can I contact Pa Auk people on this site?" 
If you do that, and if there are any Pa Auk people on the site who saw your question and who wanted to volunteer, then they might. 
So maybe ask a question like:

How can I contact Pa Auk's people? 
How can I contact Pa Auk's people?  I want to contact them about tipitaka-translation, meditation, asking, and answering. 

Also, "contact them about asking and answering" isn't very clear.  Did you mean, "I want to contact them, to ask for help with translating the Tipitaka, and with questions about meditation?" 

It would also be on-topic to ask specific questions, for example about meditation, on the main site.  I don't know what questions you would want to ask, but any question, for example (perhaps a silly question, but an example of how to format it so that it's asking about Pa Auk):

Pa Auk and jhanas
Why does Pa Auk teach that jhana meditation is optional?  Who decides, how is it decided, whether someone does or doesn't omit the development of jhana?  And how does that work in practice: are all types of student together or do they practice in different places? 

You could also search the main site to read all topics which mention "Pau Auk".