Can I add a 1099-INT if the bank will not show up?

It sounds like you are trying to download the 1099-INT automatically but the bank doesn't show up.  You can enter the 1099-INT manually.  I believe there is an option that says "I'll enter it myself".  Choose that and then type in the values in the boxes from you 1099-INT.

if you mean that you can't import the 1099-int info, then you can always add it manually.  not ever bank partners with TT to allow import.