To become a software Engineering, You can apply for entrance exam in your 12th class like JEE Main, BITSAT, SRM, Manipal and your state level entrance exam also. You can take CSE or IT branch in your engineering program.

To get admission in top colleges like NITs and IITs make sure you get 75% marks in your board exam or you should be in top 20 percentile. You can check the top engineering colleges with the given below link.

https://engineering.careers360.com/articles/top-50-engineering-college-rankings-nirf-and-careers360

Good Luck!