What is a OCC- Other Certified Credit?It's asking for a certification and project number?

If you are referring to the Indiana Other Certified Credits, the tax credit certification numbers are provided by the Indiana Department of Revenue and must be included on your Indiana tax return to receive the state tax credit. 

Certification or project numbers and PINs* are numeric characters. Enter the certification or project number you received from the authorizing entity. You can find this number in the certification letter you received from the authorizing entity, or on your IN K-1. If you also have received a PIN, add it to the right of your project number and enter the combined number in this box. For example, express the combined certification or project number “123456” and PIN “1234” as “1234561234” in Column C. Do not include any dashes.

See this Indiana Department of Revenue webpage for more information about allowable credits.