I have done my Masters in Philosophy. I am seeking enrolment in PhD international relations. Meanwhile can i write and submit a paper in International Relations subject without having done a master's in international relations?
You don't need any academic qualification to write and submit a paper to a journal. At a reputable journal it will be judged on its own merits.
But, you should take some precautions to avoid being seen as a crank by submitting sub-standard work. One way is to have someone more experienced than yourself in the field read your work and comment back on its quality and likelihood of publication. This isn't necessary, but can save you a bit of (private) embarrassment.
A really terrible paper will be rejected quickly in most cases. A marginal one might pass muster after a few revisions driven by reviewer comments.
Yes, you can submit a paper. Anyone can. Do your best to make it a good paper.