1) you can purchase second flat in joint names . make your wife co owner of flat if you so desire
2)If an individual owns more than one house property for his use, then under the provisions of the Income Tax Act, 1961 (the ‘Act’), any one property as per his choice is treated as self-occupied and its annual value is computed to be nil. The other house property is deemed to be let-out and a notional rent as per the provisions of the Act is computed as the taxable income under the head ‘Income from House Property’. In other words, the second house is treated as being rented-out and its estimated rental income is treated as taxable income.
3)In respect of such deemed let out house property, one can claim interest as deduction u/s 24(b) without any monetary limit. However, for the second house property, no deduction is available for repayment towards the principal portion of housing loan under section 80C.