I have interest income from foreign bank saving account. But I do not have a Payers TIN. What do I use for Payers TIN?

The income section asks for the TIN but it is not required to file. You can leave it blank. 

There is another question in the program that asks if you have foreign assets, be sure to select yes.

Here is a comparison of the FATCA (Form 8938) and FBAR requirements, in case you need to file one or both of those.