1. For claiming deductions u/s 24(b) the loan should have been obtained for the purpose of the purchase, construction, renovation, repair, renewal or reconstruction.
2. Only for the above purpose deductions u/s 24(b) can be claimed.
3. In your case, the nature of loan will not make a difference but the usage of the same matters. If the commercial loan is for purchase of land then it can be claimed as deductions provided land is capable of generating income which is chargeable to tax under the head Income from house property.
4. If the commercial loan is against the property and the same was not utilized for the above purpose then it will not be allowed as deductions.
Please correct me if the above interpretation has an alternative view.