First, check the home page of the State agency (http://www.in.gov/core/find_agency.html) that will be receiving the form or asked you to fill it out. Agency homepages frequently link directly to useful forms for their customers.
If you do not find the form on the agency’s website, you can search the State Forms Online Catalog (http://forms.in.gov/) provided by the Indiana Archives and Records Administration (IARA). Instructions for using the Catalog can be found in the Forms Catalog How-To (https://www.in.gov/iara/files/Forms_Catalog_How-to.pdf). For additional help using the Catalog, contact the Forms Management Program at fmd@iara.in.gov.
If you cannot locate the form you need in the Catalog, please contact the Agency Forms Coordinator (https://www.in.gov/iara/services-for-government/agency-records-and-forms-coordinators) for the agency which owns the form in question. Only the agency which provides the service you need can tell you which form to use for that service.