Hi

As you have not mentioned your category I am considering you from general category

This is a bit difficult to predict the marks required in JEE mains to get a seat in NIT trichy  as cut off rank keeps changing every year  depending upon various factors like  number of students that appeared in the exam, kind of marks obtained by them , toughness level of the jee main paper 2 examination .

When we go through previous year trend then ,
In round 6 of josaa counselling 2020 , for general neutral under home state to get Architecture (5 Years, Bachelor of Architecture) in National Institute of Technology, trichy ,615 was closing rank
You can check the same at
https://josaa.nic.in/Result/Result/currentorcr.aspx

And 615 rank is around 310 marks out of 400 marks in jee main paper 2.

So, to be on the safer side try to get at least 310 marks or more in your jee main 2021

Now,
limited time is left for jee mains 2021 , so focus on your preparation, to prepare well your jee examination, go through chapters first and your focus should be on grasping concepts , practising questions and then revising them, go through mock test paper sample papers and previous year question papers as it will let you know your preparation level and and weak areas so that you can work on them and perform well in your examination.

If you have any other doubt then you can always reach us to clear them :) we are always available to help you out and guide you

Thankyou