OK, Here are my findings.
First of all include <torch/torch.h> doesnt need building from source. its just in the a different path that is,
in include directories, one need to add both :
$(SolutionDir)Dependencies\libtorch-debug-latest\libtorch\include; $(SolutionDir)Dependencies\libtorch-debug-latest\libtorch\include\torch\csrc\api\include;
and voila you are good to go!