With the use of various realistic two-nucleon forces between the valence neutrons, three-body structure of ^6He=^4He+n+n and the short-range correlations between the halo neutrons are investigated. Use is made of the coupled-rearrangement-channel variational method with the Gaussian basis functions. The basis functions are composed of newly developed Gaussian lobe functions with infinitesimally shift parameter. Usefulness of the method is examined in the three-nucleon bound-state calculation with those realistic forces such as Paris, Bonn and Argonne potentials.