If you want to get into NIT Trichy and if you’re not worried about the department, your rank has to be below AIR 20000. In 2018, scoring 145+ in JEE Mains would put you in this position.

Here are the department specific score requirements (Data from 2018 results),

Computer Science & Engineering - AIR 4900 - 210+ in JEE

Electronics & Communications Engineering - AIR 6900 - 200+ in JEE

Electrical & Electronics Engineering - AIR 9000 - 185+ in JEE

Mechanical Engineering - AIR 11000 - 170+ in JEE

Instrumentation and Control Engineering - AIR 14000 - 160+ in JEE

Chemical Engineering - AIR 17900 - 155+ in JEE

Production Engineering - AIR 21800 - 140+ in JEE

Civil Engineering - AIR 23000 - 140+ in JEE

Metallurgical and Materials Engineering - AIR 23500 - 140+ in JEE.