HI thanks for your response. First I installed transformers using pip in python3.6. There I could import RagRetriever but I was not being able to install the module ‘datasets’ (pyarrow installation error). So I resorted to conda python 3.8 and installed the transformers module within the conda environment. There I could install ‘datasets’ module successfully but faced this import error of ‘RagRetreiver’. If you can help that will be great. I did not use any other model before in this module.