What evidence was used to gain a FISA warrant by [RR]?

Considering we can't find the original case file for the [RR] prosecution of Manafort, given that we know there was a RICO case against him and Mercury (podesta) that referenced a superseding document, one could surmise that the undiscovered case file is under seal.

A + B = C

C = FISA + [RR] Case

"Evidence", the perfect plant, a ready made criminal conviction.