interest paid on loan for property purchase, can it be treated as cost and consider for deduction while calculating capital gains. if so, is it as cost of transfer or cost of acquisition(indexed)
If you already claimed the deduction of Interest , then you can't claim it again. In my view If you have not claimed then you can include it as a cost of Acquisition, and can do indexing.
Interest paid on loan can be claimed as deduction u/s 24(b) and also under section 80EE for residential property upto 50000 rupees. But I think for calculation of capital gains you can deduct Interest on loan u/s 48 subject to if you don't have deducted earlier