I am a obc candidate, how many marks I have to score to get a good nit college.
Try to score more then 140 marks in your JEE Main exam to get admission in good NITs in OBC category other state quota.
Cut off marks varies according to the branches as well.
To score good marks in JEE Main go through NCERT books to clear your concepts and to build your fundamentals strong.
Focus on the topics which carries more weighatge in the exam.
Refer previous year papers to understand the exam pattern and to know the level of the questions.
Solve as many as mock test series for your practice.
Apart, from NCERT you can also refer below recommended books
Physics- HC Verma
Chemistry- OP Tandon
Maths- RD Sharma
Always keep in your mind that you should be determined and self motivated to crack your exam. Don't loose your hope.
All the best for your preparation and exam!!