  Unlike the case for classical particles, the literature on BGK type models
for relativistic gas mixture is extremely limited. There are a few results
%\cite{Kremer,Kremer3,KP} in which such relativistic BGK models for gas mixture
are employed to compute transport coefficients. However, to the best knowledge
of authors, relativistic BGK models for gas mixtures with complete presentation
of the relaxation operators are missing in the literature.
  In this paper, we fill this gap by suggesting a BGK model for relativistic
gas mixtures for which the existence of each equilibrium coefficients in the
relaxation operator is rigorously guaranteed in a way that all the essential
physical properties are satisfied such as the conservation laws, the H-theorem,
the capturing of the correct equilibrium state, the indifferentiability
principle, and the recovery of the classical BGK model in the Newtonian limit.
