Reduce the feasible solution $x_1=2,x_2=1,x_3=1$ for the linear programming problem $$ \begin{split} \max\ & x_1+2x_2+3x_3\\ \text{subject to }\ & x_1 - x_2 + 3x_3 &= 4\\ & 2x_1 + x_2 + x_3 &= 6\\ & x_1,x_2,x_3 &\ge 0 \end{split} $$
According to definition of Basic feasible solution, i think the given solution is already basic, please clarify someone..the two concepts.
Geometrically, a basic solution would be a corner point of the underlying polyhedron. Algebraically, since you are in $\mathbb{R}^3$, a basic solution would satisfy three constraints with equality.
You have 5 constraints, can you check how many of them are satisfied with equality?