@kumaresan29464 sounds like your TV is developing and issue with the panel. You do want to go ahead and open it up. You'll find that the main board connects to the T-con board, where two ribbon cables connect to boards which connect to the panel. Check that T-con board first. It is most likely under a sheet metal cover which you will have to remove first. Then check the ribbon cables for any tears, corrosion etc. Make sure they are fully seated. Check the board for any odd, damaged looking components. The ribbon cables control left and right side but not anything on the horizontal pane. That is done by the LCD driver boards which are the long skinny boards that the ribbon cables from the T-con board connect to. Something like like this Check those boards for any damaged component etc. Caution, those boards are not removable. So be careful when you check on those. Do not break the ribbon cables which go from the boards to the LCD panel.
It always helps to post some good images with your question. that way we can see what you see and hopefully guide you further.
It will also help if you post a short video showing what your screen looks like when it does the flickering. You can add a video the same way as you would images.
Adding images to an existing question