Hi Amrutha,
To take admission either through entrance examination or based on 12th percentage.
Since you have not mentioned the college name and course along with you have not mentioned that whether you are asking about the entrance exam or merit-based.
So it is quite difficult to answer properly. So I am telling you in general.
Some courses accept entrance marks for admission while some allow candidates through their 12 percentages.
In general, For Btech are students needs to score at least 50% marks aggregate for the general category while 45% marks for reserved candidates. In JEE mains examination, there is a criterion of 75% marks in 12th compulsory to be eligible for sitting in the examination.
Hope this helps.
Thank you and good luck:)