Hey Achal!

You have some conflicts ( someone changed the same file as you and then you need to choose which changes you want to preserve) on the project directory that probably are outside the scope of Mendix Studio pro.

For that I would recommend you to install a guit GUI to resolve the conflicts as for example SourceTree or GitHub Desktop.

There you can open your project as it is a git repository.

Hope this helps you,

If you have any other doubt about this please let me know