hey,

closing rank and cut off score differ year to year. no colleges disclose the cut off score but you may know about closing rank. see closing rank differ department wise. iist has dual integrated btech=mtech and only b.tech in aerospace engineering, electronics and communication. you need to have rank under 200 in jee main paper 2 to get selected in any b.tech stream.

for more details follow below link:

https://engineering.careers360.com/articles/iist-btech-cutoff