Yes, It is possible to get the statistics about a commit. There are two ways of doing this.
Command Line method
To get information about the commits in last one month from command line you can use following command
git shortlog --since=2021-01-06 --until=2021-01-07 -sn
Here the --since and --until is self explainatory, whereas -s is for summary and -n is for numbered.
On pytorch this gives output as follow. I have trucated the response to keep only 5 top authors.

Please note that you need the repository cloned on your local setup.
GitHub API Method
curl --location --request GET 'https://api.github.com/repos/pytorch/pytorch/commits?since=2021-01-06&until=2021-01-07' \
--header 'Accept: application/vnd.github.v3+json'
You can find the complete documentation about the API here.
There is no direct API to fetch the number of authors who have commited in last one month as the command line.
The response for the above API will need to be processed to get the count. Whereas, you can also add the parameter of author to get the commit history and effectively count of commits in last month by following API.
curl --location --request GET 'https://api.github.com/repos/pytorch/pytorch/commits?since=2021-01-06&until=2021-01-07&author=myemail@email.com' \
--header 'Accept: application/vnd.github.v3+json'
Please note that the header Accept: application/vnd.github.v3+json
is recommended and not mandatory.
Depending on your exact use-case. We can use the right API's from the documentation.