I was looking for an issue mentioned on following post:
I resolved that issue with the help of following answer on stackexchange:
you should close all active sessions windows. They still remember the old values. In other words, log out and back in. Every remote new session or a local secure shell take effect of the limits changes.
Now, I want to add the above answer to the post but as it is closed I couldn't add any comments to that post. Can someone from admin group help me to add the comment so that it could help someone in future.