MAS-HWH Mail Sleeper for today night has good chances of entering RAC. Also Tatkal one seems manageable. You may go to PRS and book both of them. In case Tatkal confirms and General stays into RAC, you may cancel the General One.
For journey till MAS, book for Brindavan - 2S.
Total cost per passenger will be around 600. (Brindavan - General + Mail - Tatkal)