Assessee-trust, running an educational institution, was registered under section 12AA and also under section 10(23C)(vi). In return for income, assessee had claimed exemption under section 10(23C)(iiiad). Assessing Officer held that assessee was neither entitled to claim exemption under section 10(23C)(iiiad) as it could be given only up to annual receipts of Rs. 1 crore in view of rule 2BC nor under section 11, due to non-submission of Form 10B along with return, which was required to be filed online in accordance with section 12A(b). The Assessing Officer rejected the request for rectification of mistake. CIT(A) affirmed the order of the Assessing Officer. On appeal, the Tribunal held that the assessee had mentioned that due to a clerical omission, deduction was claimed under section 10(23C)(iiiad) instead of the correct section 10(23C)(vi) and had submitted a rectification request to substitute section 10(23C)(vi) in place of section 10(23C)(iiiad), which was rejected. Further, required Form No. 10B could not be submitted in electronic mode despite best efforts but was submitted in physical form by assessee’s Chartered Accountant and the same was accepted by the Assessing Officer. Tribunal held that since such a clerical mistake should have been rectified by the revenue authorities, the rejection order was set aside.  Since Form No. 10B was submitted in physical form before the prescribed date of filing of return, the Assessing Officer should not have denied the rightful claim of assessee merely on the basis that Form No. 10B was not filed along with return in electronic form.(AY. 2017-18)