Hello! Hope you are doing well. To get into IIT Kharagpur you have to clear JEE Mains exam. And as for the advanced exam the cut off varies with category and branch. For a general category person to get into CSE branch, in 2018 the opening and closing ranks are 92 and 272 respectively. In 2017, it is 160 and 262 respectively. In 2016, it is 181 and 389 respectively. You can also check it in the following link:

"https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iit-kharagpur".

Hope this information is useful to you. Good luck!