6.
设全集是实数集\(R\),集合 \(A=\)\(\{ \)\(x|y=\)\(\log \) \({\,\!}_{a}\)\(( \)\(x-\)\(1)\) \(+\)\( \sqrt{3-x} \}\), \(B=\)\(\{ \)\(x|\)\(2\) \({\,\!}^{x}+m\)\(\leqslant 0\}\) .
\((1)\)当\(m=-\)\(4\)时,求\(A\)\(∩\)\(B\)和\(A\)\(∪\)\(B\)\(;\)
\((2)\)若\((∁_{R}\)\(A\)\()∩\)\(B=B\),求实数\(m\)的取值范围.