Thanks for catching this issue. I have fixed it in https://www.openstreetmap.org/changeset/165219372

The man_made=arch was supposed to be put on node https://www.openstreetmap.org/node/12287401120

This tag represents the arch present on roads outside many villages in india. Since there isn't any existing tag for this kind of feature, following https://wiki.openstreetmap.org/wiki/Any_tags_you_like, I have started tagging them with man_made=arch