Ind. Code § 5-1.4-4-5

Sec. 5. Upon the adoption of a resolution authorizing the issuance of bonds or notes, any action or proceeding in any court to set aside the resolution authorizing the issuance of bonds or notes of the bank under this article or to obtain any relief upon the ground that the resolution is invalid must be filed within fifteen (15) days following the adoption of the resolution. After the expiration of this fifteen (15) day period, no right of action shall be asserted nor shall the validity of the resolution or any of its provisions be open to question in any court or agency upon any grounds whatsoever.