assuming the IP is correct, it will take "a while" for such DNS-settings to propagate. That while can be anything from a few minutes up to a couple of days. In recent years, my personal experience shows, that this propagation will usually take a couple of hours to half a day.
@anishgiriauthorApr 23.2015 — #This website has a working subdomain. I accessed WHM and looked at the edit dns zone. The subdomain2 that I created and the working subdomain1 has the same dns entry(same IP).