$T(n)= c\times n \log n $

$\Rightarrow 2 =c \times 64 \log _2 64=c \times 384\Rightarrow c=\frac{1}{192}$

$T(512)=c \times 512 \log_2 512=\frac{1}{192} \times 512 \times 9 =24$

$\Rightarrow 2 =c \times 64 \log _2 64=c \times 384\Rightarrow c=\frac{1}{192}$

$T(512)=c \times 512 \log_2 512=\frac{1}{192} \times 512 \times 9 =24$