"Can't connect" doesn't give us much to help you with. Make and model of router? What happens when you try to connect? Are other devices, like laptops or other phones and tabs, able to connect to it? Can your tab connect to a public wifi ike McDonalds or Starbucks?
Please create a free account here, to post any responses, so that we can help you here in the thread, and not make you search all over the forum.