Vector Algebra: JEE Main 2021 Mathematics question

Let $\overrightarrow a$ = 2$\widehat i$ $-$ 3$\widehat j$ + 4$\widehat k$ and $\overrightarrow b$ = 7$\widehat i$ + $\widehat j$ $-$ 6$\widehat k$. If $\overrightarrow r$ $\times$ $\overrightarrow a$ = $\overrightarrow r$ $\times$ $\overrightarrow b$, $\overrightarrow r$ . ($\widehat i$ + 2$\widehat j$ + $\widehat k$) = $-$3, then $\overrightarrow r$ . (2$\widehat i$ $-$ 3$\widehat j$ + $\widehat k$) is equal to :