Part of the mortgage payments that you receive is repayment of the principal, and part is interest. The principal is not income and you do not report it on your tax return. The interest that you receive is investment income. If you don't know how much is principal and how much is interest you need to consult an accountant.
In order to get EIC your investment income has to be $11,600 or less. After you enter all of your income in TurboTax it will tell you whether or not you qualify for EIC.