You Could have done this any of the below ways
Case 1 : If you are Charging Interest to your Firm on Loan provided by you
In this Case your Income would be 'interest on Loan received from Your Partnership Firm'. Please Note that repayment of Prinicipal received would not be an Income to you & Not Chargeable.
Only Interest is chargeable. Against this Interest your can set-off the 'interest' that you pay to Bank for the Loan.
Case 2 : If You have Provided Interest Free loan to your Firm
In this case then there would be any Income from Firm & Nothing is Chargeable & The Interest you pay to bank cant be Claimed anywhere
Case 3: The Loan which you got from if You have Introduced in your firm as 'Partner Contribution/ Captial Contribution'.
The the Share of Profits that you Receive would be Ur Income . However as per section 10(2A) of IT Act , the share profits are exempted from Tax http://www.exploreincometax.com/Indian-Income-tax-Act-1961/Section-10
So as per section 14A of IT Act , the expense that met for earning 'Exempted Income' would not be allowed as per Section 14A http://www.exploreincometax.com/Indian-Income-tax-Act-1961/Section-14A
Hence in this case you can't claim Interest that you pay to Bank.
Source : http://www.exploreincometax.com