There are few approaches available there:
//Swift 2.0+
override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClassName.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClassName.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}
func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        if let keyboardHeight = userInfo[UIKeyboardFrameEndUserInfoKey]?.CGRectValue.size.height {
            tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
        }
    }
}
    
func keyboardWillHide(notification: NSNotification) {
    tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
}
//Objective-C
- (void)viewDidLoad {
   [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}
- (void)keyboardWillShow:(NSNotification *)notification {
    NSDictionary *userInfo = [notification userInfo];
    if (userInfo) {
    
        CGRect keyboardEndFrame;
        [[userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&keyboardEndFrame];
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardEndFrame.size.height, 0);
    
    }
}
- (void)keyboardWillHide:(NSNotification *)notification {
    tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
}