Hello

Admission to B.Tech course in NITs is done on the basis of rank of candidates in the JEE Main exam. The cutoff required for admission varies every year depending on factors such as :

Difficulty level of the exam
Number of candidates appearing in the exam
Number of seats

However, I can tell you the JEE Main 2019 cutoff for reference and to have an idea about the rank required.

Cutoff for NIT Tiruchirappalli for Computer Science Engineering branch, Home state quota is as follows-

OBC- 2165
EWS- 2058
General- 5325
SC- 1300
ST- 4708

All the Best!