  75As NMR and susceptiblity were measured in a Ba(Fe1-xCox)2As2 single crystal
for x=6%. Nuclear Magnetic Resonance (NMR) spectra and relaxation rates allow
to show that all Fe sites experience an incommensurate magnetic ordering below
T=31K. Comparison with undoped compound allows to estimate a typical moment of
0.05 muB. Anisotropy of the NMR widths can be interpreted using a model of
incommensurability with a wavevector (1/2-eps,0,l) with eps of the order of
0.04. Below TC=21.8K, a full volume superconductivity develops as shown by
susceptibility and relaxation rate, and magnetic order remains unaffected,
demonstrating coexistence of both states on each Fe site.
