Indiana's qualifying child definition is basically the same as the federal qualifying child definition. The only difference is that Indiana has a different foster child definition.
Most people don't have a qualifying child that is also the qualifying child of someone else (other than a spouse).
If a child is the qualifying child of more than one person (other than your spouse, if Married Filing Jointly), Indiana only allows the person with the highest modified adjusted gross income to claim the qualifying child for the Indiana Earned Income Credit. See instructions for more information.
If your qualifying child only lived with you during 2020, then you can claim them for the Indiana Earned Income Credit.
If your child lived with someone else (such as a parent, ex-spouse, or other relative) during the year (even if you lived with them too), you might not be able to claim your child for the Indiana Earned Income Credit.
If you're not sure if someone else could possibly claim your child, these instructions can help you decide.