Hi Reyane,
For Bachelor's in computer science, the admission is done on various basis throughout india. The most common point is the minimum eligibility. That being a pass in 10+2 from a recognised university with physics chemistry and mathematics being compulsory subjects. University usually prepare merit lists based on the marks gained by the students and then grant them admission based on that but some colleges do have donation seats which you can get. So it's better you go through the college official website and see their prospectus for clarity.
Good Luck