With only a couple of 7th  generation exceptions, the supported CPUs are all 8th generation and higher. Your system uses 6th generation CPUs and is not on the WIndows 11 compatibility list.  While that does not mean Windows 11 will not run, it does mean it is not supported, so if you decide to try it, you're on your own -- no assistance either from Dell or Microsoft.  
Hello, I failed to find which intel core cpu, among the ones compatible with windows 11, is compatible with latitude 5570. Can you please help? Thanks
latitude 5570 windows 11 CPU