I have added streets network dataset(ESRI data) for finding the shortest route but i think it doesn't take into account the historical traffic condition. Can you tell how can i add traffic data to the network dataset.
The free streetmap data that comes with ArcGIS does not contain historical traffic conditions. You can buy StreetMap premium advanced data with that information. You can get some more information here: http://www.esri.com/data/streetmap/comparison.html
Priyanka, You can add the excel sheet to ArcMap and then right-click it to either geocode or display as XY to convert the excel sheet into a point feature class. So if you have address data you can geocode and if you have lat/long then you can use the XY option. No need to convert that to something else.