Ind. Code § 8-23-7-7

Sec. 7. Whenever the department receives notice under section 6 of this chapter, the department has ninety (90) days to purchase the real property affected or commence condemnation proceedings. If at the end of ninety (90) days the department has not entered into a contract for the purchase of the real property or commenced condemnation proceedings, the owner may proceed with the improvement, subdivision, or use if not otherwise prohibited by law.