BRS stands for blended retirement system.
If you are either an active component member who will have completed fewer than 12 YOS (years of service) or a reserve component who will have fewer than 4320 retirement points as of December 31 2017, then you have the opportunity into BRS.
The new BRS goes into effect on January 1, 2018.
From BRS calculator you can estimate your potential retirement savings and outcome.