Hi @uditgaurav,

There is not a specific event which only monitor the pull request event, you can use ‘issue_comment’ instead, it will monitor comment for both issue and pull request. In the job level, use if expression to filter the comment, exclude the comments from issue.
Code sample as below:

name: pull request comment
on:
  issue_comment:                                     
    types: [created, edited, deleted]
jobs:

job01:

if: contains(github.event.comment.html_url, '/pull/')    # check if the comments come from pull request, exclude those from issue.

runs-on: [ubuntu-latest]

steps:

- name: say hello

if: contains(github.event.comment.body, '/support')   # check the comment if it contains the keywords

run: |

echo say hello

- name: test

if: contains(github.event.comment.body, '/test')  # check the comment if it contains the keywords

run: |

echo test

I tried on my repo, and it works fine.

pullrequestcomment855×710 33 KB

Thanks

Note: please use issue_comment in default branch,eg: master branch.