In your picture you show the problem at the top half of the right hand side only, is this really the only place the problem shows up ?
Also, where the problem occurs, do you get "Colour Mis-match" in other words with Black & White bars as shown, do you also see some colour around the problem area, if so then you may need to have your tube manually degaussed. Assuming this fault has only recently occurred, then it could also mean that your automatic degaussing is not working. When you first switch the TV on do you hear a sudden hiss for a second after switching on, then this is the degaussing working, if you do not hear it, then this could be your problem.
If the problem is the degaussing circuit, then the problem can be quickly fixed, but to be sure we need to understand more about the "Problem Statement"