Cutoff depends on many factors such as quality or level of paper ,No of candidates applied  and normalization procedure defines it all .
Normalization procedure by Nta equalize the level of all questions papers .

The cutoff mentioned below are in percentile are of 2019. Jee mains.
Here are the cutoff for different Category for Jee main
General-89.75
OBC-74
SC-55
St -44

If you want to know about cutoff trend for top nits then you can follow the link mentioned below

https://www.google.com/amp/s/engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches/amp

Thanks
All the very best