CBSE 12th

Hi Shubham,
Always remember, you should pursue a stream/course based on two things :
-your career goal
-the type of job you want to do
The options are unlimited, as you have done your class 12 with science. With the combination of biology, physics and chemistry you can take up medicine, dentistry, Pharmacy, agricultural science, dairy science or biological sciences (biochemistry, biotechnology, Microbiology). Apart from doing the degree level courses in science with the conventional combinations you can also choose degree courses in several emerging professional areas, such as physiotherapy, occupational therapy, nursing, computer, business administration, hotel management, tourism management etc. you can also opt for courses outside the university stream, such as hotel management, fashion technology, industrial design, packaging, aircraft maintenance engineering, government accredited computer courses and a host of post 10 + 2 level vocational courses. For pursuing a course in engineering you should have Maths as compulsory subject in 10+2.
With a PCM combination of subjects, you can pursue almost any field you set your mind on. You can ofcourse do Engineering which is a professional degree and has streams such as Electrical, Mechanical, Electronic and Communication etc. You can do your graduation in subjects of your interest, even switching to Humanities or Commerce streams if you so desire.
You can do a BCA (Computer Applications), BBA (Business Administration), Law, Civil Aviation – Pilot, Astronomy, Architecture, Design, Mass Communication, Merchant Navy, Defense Forces, Psychology, Civil Services etc. To decide on the course, you should analyse your strengths, career goals, interests, personality, aptitude and ability. If you decide based on these parameters you will put in your best effort and will be successful in your chosen field.
Hope this information helps. Please feel free to revert.
Wish you luck.