I have a SharePoint list and the items of list are not visible when opening the list in private mode of internet explorer, but the items are visible in normal mode of internet explorer.
Just use the normal mode. You might also want to try using Chrome instead and testing that in private mode to see how it behaves.
So in Private mode you have some Add-ons which are disabled which is preventing this to happen. check on the settings of IE in private mode and see if you have the same add ons enabled as in normal mode.