To create a branch from a tag

create_branch_from_tag

-Go to the starting point of the project
>> git checkout origin master
-fetch all objects
>> git fetch origin
-Make the branch from the tag
>> git branch new_branch tag_name
-Checkout the branch
>> git checkout new_branch
-Push the branch up
>> git push origin new_branch

ex.
git checkout origin master
git fetch origin
git branch release_a_branch release_a_tag
git checkout release_a_branch
git push origin release_a_branch

the short to fetch tag and checkout with this command

git checkout -b branchName tagName e.g. git checkout -b new_fixes v2.1