Indiana has a criminal offense of "nonsupport of a dependent child" which is a class D felony and it becomes a class C felony if the amount is greater than $15,000. However, filing criminal charges is normally the last step, not the first, that is taken to enforce child support. There is no certain amount that the noncustodial parent has to be behind in support, as long as nonpayment is willful.
You should contact your local prosecutor's office. They are responsible for helping parents enforce child support orders. Each county handles this their own way, but they typically first try to suspending driver's license and other non-incarceration methods before jail time is sought.
You could also hire a private attorney to seek to enforce child support.