The School Board approved the plan to file suit by a 4-3 vote.
The group says the voucher program violates law by providing tax dollars to religious institutions.
Governor Daniels calls the 2011 session a success while Democrats say some of the bills that were passed will hurt Hoosiers.
The vouchers program offers scholarships to families wanting to send their child to a non-public school.
On Wednesday, groups gathered to show support for the measures.