If one wants to become a scientist, it is good to keep interest in maths, physics, chemistry, botany, zoology and environmental science. First requirement is this. During 11th and 12 th take entrance tests for reputed institutes like IIT, IISc, BITS and many other reputed universities.
Many universities or institutes offer post graduate courses and give scholar ship. During bachelors degree there may not be a scholarship given to every one. In some reputed institutes and universities, depending on performance in each semester, a scholarship is awarded.