Usually Head office of banks provide you the formats .Long Form Audit Report you have to prepare.seepage yiu can detect by circular issued and from the loan accounts if any processing charges or cersai charges are pending yo be recovered or not
correctly stated by Mr Unnikrishnan
for revenue leakage you should go through service charge manual & try to concetrate on processing charges on renewal of facilities. Select areas on quartely/monthly basis. If possible ask for audit report of other branch of same bank. you will get more clarity.