According to the ATF, a "Permanent Brady Permit" must "for no more than 5 years from the date of issuance".
https://www.atf.gov/rules-and-regula...y-permIit-chart
So an Indiana Lifetime LTCH would never be valid for NICS exemption, per the ATF.
It's 18 USC §922(t)(3)(A)(i)(II) for those that want to look up the statute.