Inorder to have a rank under 2k your score in MAINS should be more than 230+ if you are from General Category and for other categories it may vary from category to category. So basically if you are from General Category then try to score more than 75% in class 12th and 230+ marks in JEE mains such that you will easily able to land on your respective wished branch of NIT.
All the best
IIT/JEE 2020 Online Preparation
Crack JEE 2020 with JEE Online Preparation Program, If you Do Not Qualify- Get 100% MONEY BACK