Indiana Code Title 31. Family Law and Juvenile Law § 31-19-10-1

Sec. 1. (a) Except as provided in subsection (c), only a person entitled to notice of adoption under IC 31-19-4 or IC 31-19-4.5 may contest an adoption.

(b) A person contesting an adoption must file a motion to contest the adoption in writing with the court in which the petition for adoption is filed not later than fifteen (15) days after service of notice of the pending adoption.  The motion must set forth the basis on which the person is contesting the adoption.

(c) A person seeking to withdraw consent to an adoption must file a motion to withdraw consent to the adoption in writing with the court in which the petition for adoption is filed.  The motion must set forth the basis on which the person is seeking to withdraw consent.