Held that  the computation of income and return filed together formed part of the assessment record. There was material on record to support the claim under section 11 of the Act. Thus no new or fresh claim was being raised without revising the return. The mistake was one which fell under the definition of mistake apparent from the record and was liable to be corrected without any requirement of a revised return. The Assessing Officer was to consider the rectification application of the assessee and the assessee’s claim to exemption under section 11 of the Act in terms of the information available on record or to be further verified from record.  (AY.2013-14)