hi @pshashk, I did tried to fuse model with ReLU6 activation function. It throws an error. I see in pytorch source code that fuse modules currently support 4 types sequence of modules:
  Fuses only the following sequence of modules:
    conv, bn
    conv, bn, relu
    conv, relu
    linear, relu

https://github.com/pytorch/pytorch/blob/master/torch/quantization/fuse_modules.py 22