You seem to know very little about git and merging. Please read some introduction, like git-scm.com/book/en/Git-Branching-Basic-Branching-and-Merging , then ask a more specific question.
Thanks sleske for the link, yes I am just starting to use branches. I tried some solutions before, I could solve the problem by git reset --merge but when I tried to do it again the same happen. what I want exactly is working on that branch which already existing, commit the changes, then merge them from master. is that possible? here I am a bot lost
I tried to modify those files making the conflict but no way! I solved the problem by committing from the master, this is not I Want but well!