There are very few chances for you as the most basic eligibility criteria for studying Master of Science in physics is to complete bachelor of science with at least 50% marks in the relevant specialisation. But if you try for admission in some very few universities such as Delhi University so there are chances for you to study Master of Science Physics after completing Bachelor of Technology in mechanical engineering.

This is because Delhi University is one of the very few universities which provide admission to the Engineering stream students as well in the MSc Physics course. But you must have completed your graduation in Mechanical Engineering with at least 60% marks in the aggregate for being eligible for Delhi University Master of Science Physics.

Read more about Master of Science Physics by clicking on mentioned below link:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.careers360.com/courses/physics-course&ved=2ahUKEwi1sL_tpbX1AhVExTgGHX_-AcYQFnoECAoQAQ&usg=AOvVaw2AX0tlhfn3_QHGY_LEVCeU