A coin is tossed initially.

If tail occurs,a ball is drawn from a box of 2 red & 3 black balls.

If head occurs,a die is thrown

Therefore,the sample space will be

$S=\left\{\begin{array}{1 1}H1,H2,H3,H4,H5,H6,\\TR_1,TR_2,TB_1,TB_2,TB_3\end{array}\right\}$