CBSE 12th

http://www.learncbse.in/cbse-english-core-class-12-syllabus/
you can visit the above link.

You have lot of time left. Just take out only imp book (NCERT must) and study by making a perfect routine. And, please strictly follow it. Go to tuitions regularly if necessary. Put day and night together. Wake up with determination and go to Bed with satisfaction.

It depends on cut off. Every college varies in their cut off, and that's the advantage for science student, because they can apply for arts stream as in political science hons. English hons. He can opt for language course also.

Go with BBA or B.Com.
Or else, you can opt for B.Sc or B.Tech. Mention your stream, so that I can guide you better.

Students enrolled in the XI Standard (Science Subjects) during the academic year 2017-18 and having secured a minimum of 75% (65% for SC/ST/PWD) marks in aggregate in MATHEMATICS and Science subjects (Physics/Chemistry/Biology) in the X Standard Board Examination. Students promoted through both the Summative Assessments-II conducted by the school, and conducted by the Board are eligible to apply, if they satisfy eligibility criteria. If the students have obtained a letter grade in the qualified examination, they are requested to convert it into an appropriate % marks and fill-up the application form.

Sources said, the students will only be marked according to their performance on the answer sheet and would not be allocated any additional marks. However, it has been decided that if school boards want they can continue allocating grace marks to pass students.

https://www.cedp-edu.com/diploma-degree-courses-after-12th-commerce-science-arts/
you can visit that link as per your suitablity.

You have to score more than 98% in CAT. Study well and ace it. Good luck.