In Indiana, assets received via inheritance are presumptively marital assets and subject to division; however, in certain cases, a party can argue that they should be granted a deviation (more property) due to assets received via inheritance.
The answer will depend on whether there is any type of court order granting him the right to claim the children. Without such an order, the default will generally be that the custodial parent has the right to claim. Otherwise, here is the IRS pub on this issue. http://www.irs.gov/pub/irs-pdf/p501.pdf