When trying to enable users in LSCP (Lync Server Control Panel) it will come this error, its "Insufficient access rights" See following , then user cant enable the Lync.
Finally i found solution for it.
First Go to the ADUC (AD User and Computers) and normally security tab not showing. but you can enable it in following way.Go to the View Tab,
Now its coming the Security tab, go to the user properties (Lets say Administrator) and find the security tab and go Advanced,
you should select this checkbox as shown above called "Include inheritable pemissions from this object's parent "
Now you can enable lync to the user.....