Just wanted to ask if we need any kind of wallets to recieve those tokens after the completion of campaign.And also how can token be traded into bitcoins or other cryptocurrencies.Any idea?
Read the instruction on the bounty thread most are ETH ER-20 wallets from myetherdelta or so unless specified and then once you receive your tokens is then your choice to either buy more or sale on exchange where its listed
Most of the bounties that are ERC-20 tokens request to submit myetherwallet wallet. Very few request to provide ERC-20 wallet other than myetherwallet. Some campaigns pay in terms of ethereum. This lets them trade the assets with ease rather than waiting long for the bounty tokens get listed to the exchanges.