I am a obc candidate with 56598 crl rank nd 14940 obc rank ...the best nit or iiit i can get ....plzz tell

Hii Sarvesh.
Your ranks are bit high.
As per the previous year cutoffs you have a tough chance to get Medium ranked NITs even if you get it in later rounds you might end up getting lower branches.
You can get lower ranked NITs such as NIT Patna, NIT Hamirpur, NIT Durgapur, NITs from North-east.etc
You can get some IIITs such as IIIT Jabalpur, IIIT Nagpur, IIIT Pune,etc

You can also check for Colleges on the link below
https://engineering.careers360.com/jee-main-college-predictor