cudart64_90.dll ?

I installed CUDA 9.1 and CUDA 9.0 and some different cuDNN files accordingly. But I did not get cudart64_90.dll to import tensorflow. Where do I get this .dll ?

cudart64_90 is part of CUDA 9.0
you cannot use CUDA 9.1 instead of 9.0 for this

If you want to use that particular version of TF, you must install CUDA 9.0

Got this resolved after full uninstallation of CUDA Toolkit 9.0 installed using exe(network) and installation using exe(local).