Create a tag:
To create a tag on your current branch:
git tag < tagname >
This will create a local tag
with the current state of the branch you are on.
To create a tag with some commit:
git tag tag-name commit-identifier
This will create a local tag
with the commit-identifier of the branch you are on.
Push a commit in GIT:
Push an individual tag:
git push origin tag-name
Push all the tags at once
git push origin --tags