Actually you can copy the file anywhere, just make sure to update your LD_LIBRARY_PATH so
libcudnn.so can be found, i.e. I extracted the downloaded cuDNN to
/home/at15/app/cuda(it has just two folder
lib64 ) and in my
.bashrc I added `export LD_LIBRARY_PATH=/home/at15/app/cuda/lib64:$LD_LIBRARY_PATH`.
Then open a new shell,
import tensorflow as tf should work.