Not succeeding with 11yr old son

I haven't yet achieved a successful Parent Counseling Session with any of my children.
I have a disturbed 11yr old son who really needs to talk to me about what is troubling him but we don't get along very well and he doesn't open up to me about anything. He is very intelligent and can reason and argue his way out of anything and he doesn't mind telling me when he thinks I'm lying (I don't tell lies) or asking more of him than I ask of the others. He has a very laid back nature and doesn't like to do tasks or chores or schoolwork (I'm trying to homeschool 6 children at the moment) He says he hates homeschool and wants to go back to main school.

He is one of the middle children of 10 and I know he's been missed alot in the flurry and scurry of my solo parenting. I'm concerned about the young man he will become and that there'll be no controlling him in the near future.
How do I make him a priority when all 10 are greatly disturbed and needing me every minute? How do I know which one is the priority in that moment?
How do I want to spend time with him when he continually rejects every word I say and resists me at every turn?
Other children are wanting my advice and help so I'm naturally wanting to spend time with them.
What should I think when I have the choice to work with the more receptive children or the rejective ones?
This is not very easy to say but I find him, Mum Repellent.