XF 1.5 How to handle paid and unpaid member?

Hello team,
I have two category(general and vip) section in my forum www.refixpro.com.where i want to do like only paid member will get full access of all the section.But only registers user will have access on general section not VIP area.but all user must register to post.Only paid member can get full access.
how to do it?register members can only post in General category.
can you please help me on this?
dear sir,i did not understand properly your answer.could you give me some screen shot?so i can do that exactly one by one.
thank you