Hi Anand,
Check this link: How to delete the Time Evaluation Results | SCN
Make sure to delete the relevant entries in 2006 and its corresponding entries in IT2001 or IT2002 (if there is/are deduction/s happened through these Infotypes), after deleting the old entries in cluster, re-run TE to get the relevant Quota calculated from the new Hire Date.
Regards,
Kuppan Seenu