According, to the 2017 cut off you need to secure more then 130 marks in JEE Main to get seat in NIT Srinagar in general category other state quota, Cut off marks varies according to the branches as well. 

To score good marks in your exam make sure your basics are clear. You can take help of NCERT books for your preparation. Focus on the important topics. Refer previous year papers to understand the level of the questions and mock test series for your practice.

Good Luck!!