Krishajit, have you introspected the reasons as why you were not given the rights to contribute in those sections. This site has certain policies and guidelines and if any member violates them then he is not allowed to do certain activities. Being an old member here what I will suggest to you is that please do not do the things in a hurry and just follow the policies in a proper way. Please note that these sites are a great opportunities for us to learn and sharpen our knowledge and in the process earn points as well as sometimes cash awards also. So, before submitting anything just check some sample articles here and make them your bench marks. Try to contribute at least of that level quality content. Another important thing is that copy paste is strictly prohibited here and once a member is caught doing like that his rights to contribute would be removed for a long time.
Please take these things in this perspective and I have seen that you have a good potential to write the content but probably you require to do some more hard work in the line so that your content is accepted for publication. The last thing I want to advise to you which I am time and again advising to new members is that check and edit your content for grammar, spelling and other such things before submitting. Use 'Grammarly' App if you are not good at last minute editing. I hope these things and measures would help you and based on your track regard the webmaster would soon allow you to post your contents. I am afraid if you had violated some policy thing in the past then you would have to wait for your reinstatement for quite some time.
If you have any doubt, feel free to interact.
Knowledge is power.