Normally there are 5 or 6 user online on my forum but now there are 29 user active.. when i see there ip i find that near by all guest ip are start with 213.186.127.9 and last digit are change 213.186.127.x
What is that help me..
Probably spam bots attempting to register. I wouldn't worry about it unless you start getting lots of spam accounts being created.
Have they registered or is it just guests browsing your forum?
You shouldn't be banned from adsense for having guests browsing your forum. There's not really much you can do about guests, for example mybb community forums currently have 374 guests online. If your worried about being banned from adsense because of guests clicking the ad, maybe make it invisible for guests.