When you rent below fair market
price, you would be considered to be renting "not for profit."
If your expenses (mortgage interest plus
property taxes) were more than the rent you received, you are not required to
report the income.
Otherwise, the rental income for this period
is reported as Miscellaneous Income in the Less Common
Income section at the bottom of Wages & Income.
If this is a "second home",
property taxes and mortgage interest may be included as Itemized Deductions (Your
Home under Deductions & Credits).
If the rental income exceeded the property
taxes and mortgage interest for the property, you may deduct additional costs
associated with the house as miscellaneous itemized deductions (Other
Deductible Expenses under Other Deductions & Credits).
The total of property taxes, mortgage interest, and other expenses that you
deduct cannot exceed the amount of rental income you received.