how to create report viewer group and associate reporting rights? similarly how to create other group and associate permissions or rights? if any users belong to any group (security --security roles) default group able to access console do some task?) for e.g OSD manager group able to access?

Kent Agerlund has it covered here: http://blog.coretech.dk/kea/creating-the-reporting-user-role-in-configmgr-2012/