Dear you are talking about deduction of borrowings taken for construction of house which is self occupied.
here is details , hope it will clarify ur doubt-----
Maximum tax deduction for repayment principal component of home loan can't exceed Rs 1,00,000 under section 80C. One should keep in mind that other investments/contributions are also allowed as a deduction under section 80C, and this limit of Rs. 1,00,000 applies to all of them put together.
Housing loan interest deduction, on the other hand, is allowed up to a maximum amount of Rs 1,50,000 under section 24(b). However, the acquisition or construction of the house property should be completed within 3 years from the end of financial year in which home loan was taken; otherwise, the amount of interest benefit allowed is only up to Rs 30,000.
Furthermore, the above tax deduction limit u/s 24(b) is applicable only for self-occupied house property. In case of let-out or deemed to be let out house property, interest is deductible without any limit.