@erohmensing thanks for your prompt reply, issue got resolved. Error occurred because of versions mismatch in dependent packages of tensorflow-1.12.0.
For installing tensorflow-1.12.0 in windows laptop(without internet connection, downloaded packages from pypi.org website) I have used below versions and successfully installed Tensorflow.
Python version used : 3.6.1 Dependent packages: astor-0.7.1-py2.py3-none-any.whl termcolor-1.1.0.tar.gz Keras_Applications-1.0.7-py2.py3-none-any.whl absl-py-0.7.0.tar.gz numpy-1.13.3-cp36-none-win_amd64.whl protobuf-3.6.1-cp36-cp36m-win_amd64.whl Keras_Preprocessing-1.0.9-py2.py3-none-any.whl Keras_Preprocessing-1.0.9-py2.py3-none-any.whl Markdown-2.6.8.tar.gz tensorboard-1.12.2-py3-none-any.whl grpcio-1.18.0-cp36-cp36m-win_amd64.whl gast-0.2.2.tar.gz tensorflow-1.12.0-cp36-cp36m-win_amd64.whl