Assuming you are referring to a Tax Credit Certification Number for the Indiana School Scholarship Credit:
In the Indiana state interview, when you get to the Credits section, select School Tax Credit. You can enter the TCC Number on this screen:
The receipt letter you receive from IQE will have the amount of the donation and the tax credit certification number (TCCN). The TCCN is provided by the Indiana Department of Revenue and must be included on your Indiana tax return to receive the state tax credit. Report the amount of the tax credit (50 percent of the amount of the contribution) on Schedule 6, line 6. The credit name is School Scholarship Credit and the code number is 849. Also, complete and attach Schedule IN-OCC with the year of your donation in column B, the certification number (TCCN) from your receipt letter in column C, 849 as the code in column D and the amount of your credit in column E.
See this Indiana Department of Revenue webpage for more information about state tax credits.