Hello RameshKumar,

First and foremost criteria to get any NIT's would be clearinf your JEE mains with a good percentile. And Secondly, you must have a minimum PCM aggregate of 75% since that's the minimum eliglibilty criteria. NIT trichy is one of the most premium NIT's and cutoff ranks are indeed very high. So, your JEE score must be high so as to get a good rank. I'll hereby attach a link to for you to get an idea about the  opening and closing ranks for several courses(Last year trends).

https://www.careers360.com/university/national-institute-of-technology-tiruchirappalli

Hope that helps

All the best