Loan taken on FD is sublent to other for interest.

In case of IFOS, any expenditure other than capital expenditure or personal expenditure which has been incurred wholly, necessarily and exclusively for earning income like revenue expenditure, such expenditure will also be allowed as a deduction.

Since you have said that the loan taken by you is personal you cannot deduct Rs 81000/- from (45000+85000/-).

If you can prove that you have borrowed funds just to invest in your friend's business, you can claim the interest paid 81000/-against the interest income received 85000/-. 

In any case Rs 45000/-(FD int) will remain taxable. [Where an assessee had invested money in a fixed deposit in a bank on interest, and had taken a loan on the security of that deposit from the same bank on interest, the interest paid by the assessee on the loan would not go to diminish his income from interest on the fixed deposit paid by the bank. Such diminution is not covered by any provisions in the law - CIT v. Dr. V.P. Gopinathan [2001] 248 ITR 449 (SC).]