Hello Jyothirmayi, I think that you not need any type of permission and you also not need to request webmasters for posting each article. You can post article on any of your own choice. There is no need for permission for each article. In the resource topic section, members can submit the good topics and also request for the topic on which he wants to write article. As suggested by our above webmaster, members can write on that topics and also write on the other topic too. I hope that your doubt is clarified in this thread.
Regards,
Amit Singh