If you're able to delete the payroll processes for the person, after 30-June-2011, then you can terminate the person on 30-Jun-2011.
But as you must have already closed the year 2011, it might not be feasible to delete back-dated payroll runs.
So, the only thing you can do is terminate the person as of a date on/after the latest payroll was run for the person.
Say the latest payroll run was 31-Aug-2013 for this person, then you can only terminate the person on or after 31-aug-2013.
Thanks for the reply.
My functional consultant was back and he resolved the above issue.
1. He deleted the Payroll entries of only that employee through view>Assignment Process Results.
2. Make the "End Employment " with the correct effective date. People>Others>End Employment.