My country is Bangladesh setup

I'm guessing that you may have an iPhone, are trying to set it up and you are located in Bangladesh and can find not setting for that. Is this correct? If that is the case, there are no supported carriers for the iPhone in Bangladesh, that is why you cannot find settings for that. Wireless carrier support and features for iPhone in Asia-Pacific - Apple Support

So what is your question? See this, https://discussions.apple.com/docs/DOC-5931 and come back with a detailed question.