Does Nigeria law have an extension for a yearly tenant after 6months notice have been served?

When the 6 months notice expires, he will serve you another 7 days notice. After the 7 days notice expires and you still remain in the property, he will file action in Court and get judgment to take over the property. So, his right to take possession is not automatic upon the expiration of the notice. The case may linger in court for another 6 months or even more before he can get a judgement to take over the property. But like you rightly said, you need a lawyer. Thank you.