You can probably sell it in Digital Goods but keep in mind that there's a lot of scammers on both sides so understand that people will be suspicious of you and you should be suspicious because anyone can be a scammer online.
It has been mentioned several time above that Digital section is where he needs to sell but there are also some technicalities in selling a Gambling Account specially VIP rank but there are some offers i read about the desire in Buying VIP ran though they are looking for some specific Gambling site account in which not mentioned by the OP that he owned.
I guess this forum has selling section.
Check post above and yes you'll find .