Hi Aravindhan

I see that you pursued 12th this year and now you want to study B.E. in Computer Science. There are many Government and Private colleges as well as universities where you can pursue your B.E. and the JEE Mains is the exam by which you can get into these colleges as well as universities, even the private institutions prefer the marks of this exam. JEE Mains in conducted by National Testing Authority(NTA) which is held twice a year in January and April as well .

Eligibility : You must have scored minimum 75% in PCM, for SC/ST it is 65% in your 12th

Or you should be in top 20% percentile of your respective board, moreover there is no age limit for appearing in this exam.

How to apply : Just visit the official site of JEE Mains Exam and Fill the form afterwards upload your photograph and at last submit the examination fee 

No. Of attempts : The candidates can appear for exam in three consecutive years, whereas the exam being held twice a year .

And when you clear your examination you get to choose the college you want based on the marks you get in the exam . The Top 5 Colleges/Universities of India are 

Indian Institute of Technology Bombay

Indian Institute of Technology Delhi

Indian Institute of Technology Kharagpur

Indian Institute of Technology Madras

Indian Institute of Technology Kanpur