The stability of FeC⁻ against dissociation in an astrophysical environment was probed by the collisional excitation of FeC⁻. Two anion resonances yielding Fe⁻ and C⁻ fragments were observed and studied through measurement of the kinetic energy released during fragmentation. The yield of Fe⁻ was found to be nearly 5.5 times more than that of C⁻ indicating the C⁻ fragment to be in the loosely bound (²D) state. The possibility of avoided crossing leading to the observed fragment ion yield is also discussed. The dissociation of FeC^-_n (n = 2 to 4, 6) cluster anions predominantly resulted in the cleavage of Fe^–C bond yielding only C^-_n fragments with similar energy release. The yield of C^-_n is discussed in the light of the observed abundances of HC_n in IRC+10216. The importance of rotational transitions pertaining to both the ground and excited-electronic states of these cluster anions is discussed.