Hi there,
If someone like my competitor goes on my website and clicks so many times so that Google ban my Adsense account then Google will tell about it or can i make request that it was not me or my referral or made so many clicks it was actually my competitor who did this.
Share your experience?

Am hearing it for the first time and am also very curious about it

no, i didn't get any replies about that

You can find out your all answers in google adsense FAQ. Then you can realize what is legal and illegal for google ad sense. 

google is smart enough to find out that your competitor did this or you...

They usually tell the reason but hardly listen anything against their decision.

So Adsense is always a big risk..

Hi.
Google is very clever and going against it will be very risky.