Indiana Code Title 3. Elections § 3-8-7-27

Sec. 27.  If two (2) or more conventions are called by authorities claimed to be the rightful authorities of a political party, the commission or county election board shall select suitable devices to distinguish one (1) faction from the other and have the ballots prepared accordingly.  However, if a political party entitled to nominate by convention fails to do so, the names of all nominees by petition for any office who are designated in their petitions as members of and candidates of the party shall be placed on the ballot under the name and device of the party on the ballots, as if nominated by convention.