hello,
to study btech in computer science engineering you need to give jee main. as jee main exam consider for most of the engineering colleges in India.
please check the below link for the list of entrance exam for engineering
https://www.google.com/url?sa=t&source=web&rct=j&url=https://engineering.careers360.com/exams&ved=2ahUKEwiaw7_zoebhAhWI73MBHRm5AngQFjABegQIDhAF&usg=AOvVaw3TRzyhgVJ50HEqsB4w4_HK

there are some deemed university like satra Tamil nadu, amity university.
you can apply there also.