Spammer

There is a memberin my forum that repeatedly insults other members, i first issued him a Ban (Later he repented very seriously to me and started begging me to get him back on my forum) after that he went as quite a good member for a month then again started insulting other member, we IP banned him, but he is creating a series of accounts and constantly repenting, but I hardly think i must get him back on the forums

So My Question is, is there a method from which i can stop him from creating any more accounts?

There is no use IP banning him, because probably he uses proxies.
Your best option is to go on banning his account, when you know its him. Just ban him without saying a word. Just ignore, just be normal. Don't show him that you banning him all the time, is a trouble for you. He will leave your site alone once he gets bored. But, if you show you are troubled, he will do it more.

He uses a 35 IP address, so there is no option?

Try to ban him on email.

He uses many Email IDs

Well, i already advised whats the best option