A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made (particle physics) to the behavior of the material Universe as a whole (cosmology).
To be an physicist first you do your under graduation programme in physics (B.Sc physics ) after your plus in top institutions like Loyola or PSG. During your under graduation start preparing for JAM (Joint entrance examination for M.Sc ) for admission to M.Sc in physics in IIT or university of Pune . You need to qualify and get good marks in JAM examination for your admission after your graduation. After your masters you do your Ph.D in your relative area to become an Physicist.