I want to know how can I assign a minimum post to view my board? For an example I have a board namely General Topics, only a member(s) who has 10 posts can view General Topics.

You need to make a rank,If the user has 10 posts s/he automatically gets that rank,and can enter that forum.

AdminPanel>Users/groups tab>Rank administration>New rank>minimum posts:10>special rank:no>color:If you want(I don't care)>then make the forumfor people In that group/rank.

oh thanks for early response I've been seeking it from the whole forum but I can't see it..

Ranks has got nothing to do with permissions of viewing a forum.

Create groups with the auto subscribe feature such as group x , minimum # of posts 10.

Then give permissions for only that group to view that forum.