Dear G Pathireddy,

As we know reservations are governed by the guidelines of government, for NITs there are two types of reservation/quota. They are Home quota and Other state Quota. All most 50% of seats are reserved for home state quota students.Cutoffs may vary from year to year according to branch and it depends on difficulty level of examination, no.of seats available. 

State of Eligibility: It is the state from where the candidate has passed the qualifying examination. 

The reservatin criteria in NITs is shared below:

Https://engineering.careers360.com/articles/jee-main-reservation-criteria

All the best...!!!