GSTR2A ITC Amt

You need to reconcile the difference and check if some invoices are not posted in your books of accounts.

You may need to follow up with supplier for submission of invoices.

In some cases, there may be ineligible gst credit in the account. For example, if there is purchase of a car, gst may be there is account but not eligible (restricted credit). 

In such a scenario, you need to take credit only which is egilible and available for utilisation.

Only a proper reconciliation can help.in arriving at right amount of GST Credit.