It is not possible to watch 4k TV on an HD Ready 720P TV. HD Ready 720P TVs have a resolution of 1280x720 pixels, while 4k TVs have a resolution of 3840x2160 pixels. This means that a 4k TV has four times the number of pixels as a 720P TV. In order to display a 4k signal on a 720P TV, the signal would need to be downgraded to the resolution of the TV, resulting in a loss of detail and clarity. Additionally, most TV channels and streaming services do not broadcast in 4k, so even if it were possible to display 4k content on a 720P TV, there would be limited availability of that content.