Sec. 153C of Income Tax Act, 1961—Assessment—Assessee has not given any explanation regarding the nature of mistake and no document such as books of account or bank statement or cash flow-statement has been filed by the assessee, further, the proceedings u/s. 153C cannot be used by the assessee to reduce his income and if assessee wants to reduce his income, he has to file revised return of income- Completed assessments can be interfered with by the AO while making the assessment under Section 153 A only on the basis of some incriminating material unearthed during the course of search or requisition of documents or undisclosed income or property discovered in the course of search which were not produced or not already disclosed or made known in the course of original assessment - MUZIBUR RAHEMAN KHAN V/s ASSTT. CIT - [2020] 28 ITCD Online 011 (ITAT-CUTTACK)