Dear Sir,
With respect to your details please find following details :
1. You can claim interest paid in the year 2012 - 13 to 2014 - 15 in respective income tax return as loss under house property and get it adjust against any other income up to amount of Rs. 1,50,000/- per annum.
The working done by you is no where have any legal backup or defined under income tax act for tax benefit.
2. You can claim the amount of principle repayment under section 80C up to Rs. 1,50,000/- & Interest on housing loan of Rs. 1,50,000/-. Once you pay of this loan there can not be any benefit in future years for payment made in current year.