Thanks for your interest in the Bluemixathon. I'm sorry, but Nigerians are not eligible for this particular competition.
We wish we did not have to exclude countries from global competitions. Unfortunately, it is legally complicated to run prize-based competitions in some countries due to local contest regulations. By no means is this a statement as to whether international developers are valued or not. They are! It's just a matter of complying with US and local laws.
You are still certainly welcome to create an app using Bluemix and post it to your portfolio, but unfortunately you will not be eligible to win a prize in this competition.