Input tax credit

hi

Input Tax Credit We are taken as less amount than the actual Amount due to clerical  mistake

( Instead of 100000 we are taken as 10000)

but this is happened in Aug'2011 but we found it on Feb'2012

any way  Vat 213  is not possible to submit  becuase of 6 months over.

We are not ready to loose this amount as a Clerical mistake

Can we do Staraight way can we increase our Credit to this extent or else need to submit the vat 213.

What is the alternate for us.Please guide us.

Thanks & regards

Ramesh Reddy