As per the official documentation, I have created the Eventual directory and Symbolic links(_add pointing to filestore & _pre pointing to _pre) within it. The automatic migration does not happen. I am using docker container of artifactory pro version 6.23.13 . I have waited overnight for the migration to happen but it didnt. Also the artifactory was serving only 4 artifacts.
Answering to my own question, I had initially created the eventual directory and links in the path /var/opt/jfrog/artifactory which is the home for docker container. Seems like there is another path that exists within the container /opt/jfrog/artifactory and creating the directory and links in that path seemed to do the trick