Hi,<br>In drupal, i have seen some modules and it's functionality. I think these modules with minor changes in it will fulfill our requirement. Modules are listed below,<br><ul><li>Organic Group (og module) : <br></li><ul>
<li>Enable users to create and manage their own 'groups'. <br></li><li>Each group can have subscribers, and maintains a group page where subscribers can post into.
</li><li>Membership to groups may be open, moderated, or invitation only.</li><li>Any page,forum,poll etc. created by a user of a group 'A' can/cannot be access by a users of group 'B'.</li><li>Any post created by a user of group 'A' can/cannot give access to users of group 'B'.
</li><li><br></li></ul><li>og block visibility module : <br></li><ul><li>This module allows you to specify that a block should be visible only within selected groups.</li><li>This
can be used for many purposes, from providing each organic group with
its own navigation menu, to allowing a group to highlight its own
featured content, etc.</li><li><br></li></ul><li>og forum module : <br></li><ul><li>Upon creating an og group, it creates a forum container for that group, with a single sub-forum.</li><li>A record is also placed in og_term to tie the organic group with the forum container's term ID.
</li><li>When viewing groups, only forum discussions for that group are displayed.</li><li>The og_term table could be useful for other applications of tying groups to taxonomy as well.</li><li><br></li></ul><li>og mandatory group module :
</li><ul><li>An add-on for the Organic Groups module that makes one group mandatory for all new users.</li><li>Choose
one group that all new users will be put into. You can chose either an
open or a closed group. Any new user will be auto-approved as member of
the group. The group manager(s) of groups that a new user joins will
get an automatic e-mail notice.</li><li>This module also allows the
admin to require a new user to join at least one group during
registration by requiring them to choose one of the groups listed in
the registration form. This group is in addition to any mandatory
group. This feature is disabled by default, is independent of whether
a mandatory group is selected, and has no effect if there are no groups
listed in the registration form.</li><li><br></li></ul><li>og moderate module :</li><ul><li>Moderate
public posts from organic groups module. Moderated posts will be hidden
from anonymous visitors. Moderation needs to be done by node
administrators or another module.</li><li><br></li></ul><li>og roles :</li><ul><li>This
module allows you to, for each group type, specify a list of roles that
group administrators are allowed to assign. In the subscriber list
(og/users/<node id>), a 'configure member roles' tab will appear
if both the group type is allowed to configure roles and the current
user is an admin for the group.</li><li>For example, if you created a
"trusted user" role, and a new node type called "official group," you
could allow administrators of only official groups to add selected
other group members of to the "trusted user" role.</li><li><br></li></ul></ul>Regards,<br>-- <br>kanhaiya kale (KK)