Hi @MithunB,
fiddling with the configuration file is not needed and not recommended in the Docker context (no persisting of the data).
Please verify if the connection to the S3 is possible by inspecting the rails-server container log and running the following command.
docker container exec RAILSERVER_CONTAINERNAME /docker-entrypoint.sh /opt/zammad/bin/rails r 'Rails.logger = Logger.new(STDOUT); pp Store::Provider::S3.ping?'
The container name should be equal to zammad-railsserver (or at least include this substring.) See tip box in the storage documentation
P.S. The force_path_style option will probably not work with the origin AWS S3. You should consider the AWS S3 documentation, desperately.