Dear Parag,
it depends on the reason why you are interested in using the 5.9 GHz band. SimuLTE uses the band parameter for channel-modeling purposes, i.e. for computation of the signal propagation etc. You can change/modify the channel model used, if you want. However, to the best of my knowledge, the rest of the upper-layer functions should not depend on the actual band being used.
Please let me know your thoughts about this.
BR
Antonio