Assessee had earned certain amount of exempt income in form of dividend and interest from NHB bonds.  It claimed same under section 10(34) but did not make any suo motu disallowances under section 14A of the Act.  Assessing Officer computed disallowance under section 14A by invoking rule 8D and determined disallowance of interest and other expenses. Held that  since assessee maintained common set of books of account for taxable and exempt income, possibility of incurring common expenditure for both segment could not be ruled out and, therefore, Assessing Officer was justified in invoking rule 8D to compute disallowance however  with regard to interest disallowance under rule 8D(2)(ii), since assessee had not filed any cash flow statement to prove availability of own funds when those investments were made during relevant year, matter was to be remanded back to file of Assessing Officer to verify facts with regards to availability of own funds to explain investment made in shares and securities which yielded exempt income. (AY. 2011-12 to 2016-17)