The high-temperature stable defect complexes in 6H-SiC crystals created by heavy neutron irradiation and following high-temperature annealing have been discovered by EPR. After annealing at 1500° C at least five new axially symmetric centers with the electron spin S = 1/2 and S = I were shown to arise in 6H-SiC crystals. The striking feature of all discovered centers is a strong hyperfine interaction with a great number (up to twelve) of equivalent host Si (C) atoms. Two models, a four-vacancy complex V-si-3V(c), and a split-interstitial antisite (C-2)Si or a pair of two antisites (C2)Si-Sic are discussed. There is a good probability that some of new centers could be related to the famous D, and D-II centers. After annealing at 2000° C the dc1-dc4 centers disappeared and a new triplet center labeled as N-V in the form of a silicon vacancy and a nitrogen atom in neighboring carbon substitutional position has been observed. The parameters of this center are similar to that for well-known N-V center in diamond.