Does UPSC declare marks of IFoS(Mains) of those who are not selected for interview?

I am asking this because I am sure that I will not qualify mains as I have not prepared forestry and my GS and optionals are also weak. So I am preparing for next year IAS. I am planning to write IFoS mains for knowing my optional preparation(how much I improved after IAS mains)as syllabus of my optional is quite same in both IAS and IFoS.