I guess there is no such quota for booking tickets -- it is for recruitment.
But one can avail concession under the category "Sportsmen" while booking .. if going to participate in all India/state tournaments /national tournaments.
concession will be --
-- 75% in 2nd and SL class
--...
more... 50% in 1st class
..
A certificate from the secretary of the concerned sports association will be
reqd. while booking at counter