For all the Top 6 IITs, the opening and closing ranks for CSE branch which is in high demand and receives ample of applications, stands at 1-100 rank, viz top 100 AIR are having great chances.

For branches like Mechanical and Electrical which are core, the ranks open up at 100 and close down nearby 500.

Alternatively, you're supposed to score 305+ for achieving top 100 ranks and range from 275-285 for ranks below 500.

Entire cutoff range and best preparation tips has beenn shared below for reference:-

https://engineering.careers360.com/articles/jee-advanced-cutoff

https://engineering.careers360.com/articles/jee-advanced-preparation-tips-physics-chemistry-and-mathematics

All the Best..!!