Best of luck for Munabao to you. I suggest you to go from Barmer station by train no. 54881/54882 BME-MWF passenger. I also visited Munabao from Barmer on 17th January 2017. Becareful if you are going Munabao 1st time because Munabao is international border restricted station you have to give some security answer in Munabao station to CRPF/BSF.
Question Ex; why you arrive munabao it is international border restricted station. Nobody is allow to come here ? where from came from ?