Hi Sruthi,
You can download Tortoise SVN/Git, and in the file explorer, where your file is, you can right-click and then go to Tortoise SVN/ Tortoise Git (depending on your project ) and then click on resolve, this will resolve the external conflict, and you will be able to commit.
Let me know, if you have any issues,
Hope it helps!
Rishabh Shandilya
(Resilient it services)