Hey nandan10, cool you are also joining the OSM community. It was raised in the global chat that you are creating changesets (CS) just commented with "testing". Can you please use a more desribing name - here for example "Changed roundabout from motorway to service" so its easy to follow and check. 

Now on this CS: You demoted the motorway to service and checking with the wiki https://wiki.openstreetmap.org/wiki/Tag:highway%3Dservice it seems wrong unfortunately. Can you tell us why you did that? 

Best regards