After browsing a lot , i was not able to find exact method to install tensorflow on my arch linux.
As on tensorflow documentation they suggest to compile from source for linux other than ubuntu.
It gave me lot of errors.
Next I tried the other way, using pip ir pip install tensorflow-gpu , but that gave some errors using cuda 9.1.1 and there seems to be no cuda9.0 for arch
Then finally this worked
sudo pacman -S python-tensoflow-gpu
(it gave conflicts with old python , in case you get those remove old python first )
As on tensorflow documentation they suggest to compile from source for linux other than ubuntu.
It gave me lot of errors.
Next I tried the other way, using pip ir pip install tensorflow-gpu , but that gave some errors using cuda 9.1.1 and there seems to be no cuda9.0 for arch
Then finally this worked
sudo pacman -S python-tensoflow-gpu
(it gave conflicts with old python , in case you get those remove old python first )