The article you read was contributed to Education.com by the Indiana Department of Education. You can contact them directly to see if the information provided in the article ("age 5 on or before July 1") is still accurate. Here is their website, which includes several means to get in touch with their staff: http://www.doe.in.gov/
You can also research the phone numbers for your local school district and school in SchoolFinder: http://www.education.com/schoolfinder
Contacting the local school or district could be a quicker way to get the answer to your question and learn more about kindergarten enrollment policies and procedures.