Can anyone let me know the GRE score required for Masters in Aerospace?

GRE testing is optional and only necessary for some departments in Europe or Canada. Universities consider an applicant's complete profile. A low GRE score does not automatically rule out admission to prestigious schools like Stanford. Many prestigious universities have admitted students with GRE scores of 310 while rejecting those with 335! So, don't lose hope. 

An MS applicant should excel in all areas, including academics, extracurricular activities, work experience, etc. 

It is best to start working on yourself from the second year. Look for internship opportunities at prestigious universities. Complete projects, make an impression on your professors to earn recommendations, apply for URAs, attend international and national conferences, and work to publish your journal articles. Try university internships abroad at the end of your third year in Canada, Germany, the US, etc. 

In a perfect world, one would start preparing for the GRE during the internship and take the GRE and TOEFL at the start of the end semester. According to test scores and profile, pick universities and courses carefully, and develop your SOP and resume by October. Look at financial options.

If your GRE (GRE=315) is bad, you might not get into all the US Universities. Therefore, both a strong SOP and resume are crucial.