Okay Sometimes is the best when you Help yourself and dont ask in a Dead Forum. So In case someone has the same problem, here is the Solution:
Vector2f buttonSize (300, 300);
Vector2f buttonPosition (100, 800);
RectangleShape Button;
Button.setSize(buttonSize);
Button.setPosition(buttonPosition);
FloatRect buttonTouch (buttonPosition, buttonSize);
if(buttonTouch.contains(Touch::getPosition(0).x, Touch::getPosition(0).y){
//Set the other rectangle fill with Color
}