DDR2 Fitter(Place & Route) report errors

Have you checked the pin assignments in the Memory generator (ALTMEMPHY). Make sure the pin assignments do not conflict with other pin assignments in your project/board. I guess, you also need to choose a memory vendor aka Micron/Samsung/etc from the Memory vendor list so that you are targeting the correct memory chip. Each chip has its own timing parameters so be careful in selecting the vendor and chip carefully from the supported memory list.