The term UTR No. means Unique Trasaction Reference Number and it is generally used in association with NEFT transactions done through bank.  For every successful NEFT transaction, your Bank will provide a UTR number (Unique Transaction Reference No.). For example, if you do the a NEFT transaction with a branch of Union Bank of India, the Union Bank of India will provide the UTR No. to you which can be used to track the transaction later. So, UTR number is a unique code for identifying the NEFT transaction.

Please note that to make NEFT transaction, you need following details of the beneficiary account – Name of the Account Holder, Account Number, Payee Bank Name, IFSC Code of the branch.

E.g.

For Bank Clerks IBPS CWE Exam, Use –

Name of the Account : IBPS CWE- Clerical Cadre- 2011
Account Number : 005120110000778
Payee Bank : Bank of India
IFSC Code : BKID0000051

For Bank PO IBPS CWE Exam, Use –

Name of the Account : IBPS CWE- Officers’ Cadre- 2011
Account Number : 005120110000667
Payee Bank : Bank of India
IFSC Code : BKID0000051

Once transaction is complete, you will receive the UTR No. from the bank which can be quoted for any query later regarding the transaction.

Update: Regarding confusion of BOI to BOI transaction. I called the BOI customer care desk available at http://www.bankofindia.com/contactus.aspx and enquired about the confusion. They said 270711cXXXXXX is the UTR Number and needs to be entered in the CWE Exam application form. Confused people should call again to confirm and do update the status in comments to help others.