If it's not the same MCU, I highly recommend you to create a new CubeMX project with your specific MCU and reset all the parameters to match your current config with the Disco board. It's only a matter of copy pasting and this should not take too much time ;)
Simply change the QSPI pins in CubeMX according to your new pin map and regenerate code. Maybe other parameters need to be changed if it is not the same QSPI as the one on the F746 Disco board.
I don't know if you did it but as mentioned previously, I recommend you to create a new CubeMX project with your specific MCU.
I have working project with 480*272 pixel size. Now I am trying to change pixel size to 800*480. Can we achieve this by just changing the parameters of LTDC in ioc file.
My display now flickers when contents on display changes.
If you change the screen resolution I guess you are trying to change the screen itself. I also suppose from your message that you use LTDC displays. Changing the resolution is not enough. You need to match all the settings of your new screen (front porch, back porch, etc.). The LTDC clock must be higher if your screen has a higher resolution.
Please create a new thread with explicit title when your question is unrelated to the current thread subject. I will not answer anymore on this thread.