CBSE 12th

You should have passed 10+2 examination with minimum 60% from CBSE or any other equivalent examination board with Physics, Chemistry and Mathematics as core subjects. Bachelor's degree programs include classroom, laboratory, and field studies in subjects such as general engineering principles, propulsion, stability and control, structures, mechanics, and aerodynamics, which is the study of how air interacts with moving objects. Some colleges and universities offer cooperative programs in partnership with regional businesses, which give students practical experience while they complete their education. Cooperative programs and internships enable students to gain valuable experience and to finance part of their education. Top colleges:
Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore
International Institute of Aerospace Engineering & Management (IIAEM-Jain University), Bangalore
Indian Institute of Science (IISc), Bangalore
Indian Institute of Technology, Bombay IIT Mumbai
Lovely Professional University, (LPU) Punjab
Indian Institute of Technology, Kanpur IIT Kanpur
Indian Institute of Technology, Madras IIT Chennai
Indian Institute of Space Science and Technology, Thiruvananthapuram IIST Thiruvananthapuram
Indian Institute of Technology, Kharagpur IIT Kharagpur
Indian Institute of Engineering Science and Technology, Shibpur (IIEST-S), Howrah
Madras Institute of Technology, Anna University, Chennai
Birla Institute of Technology, Mesra, Ranchi
Defence Institute of Advanced Technology (DIAT/IAT), Pune.

You have to give BITSAT test for entrance into BITS.
There is a provision for board toppers for direct admission.
Check this link for eligibility:
http://www.bitsadmission.com/Eligibility_Criteria.aspx
http://www.bitsadmission.com/bitsat/BITSAT2018brochure.pdf?id=new
Direct Admission to Board Toppers:
In the past, admission process of the Institute always ensured guaranteed admission to all the students who obtained first ranks in their respective board examinations. This has given a very vital input of highly meritorious students from all over India. First rank students of all the central and state boards in India for the year 2018 will be given direct admission to the program of their choice, irrespective of their BITSAT-2018 score, as per the eligibility criteria mentioned above. Further details about this scheme will be available at BITS admission website by 1st of May 2018.