how much rank should get to do BTech IT...?
Dear candidate, different colleges have different cutoffs for different branches. Cutoff for CS/IT is usually high in different exams. However, you not mentioned name of college, I assume you are asking cutoffs of IT in best engineering colleges:
For cutoffs of NIT you can visit:
https://engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches
For cutoffs of IIT you can visit:
https://engineering.careers360.com/articles/jee-advanced-cutoff-for-iits
For cutoffs of bits you can visit:
https://www.bitsadmission.com/bitsat/2021/BITSAT-2020%20Cut-off%20Scores.pdf
Hope, it helps!