how many marks should we get in jee mains so dat i get a seat in nit tiruchurapalli..mechanical branch?

Dear Student,

It depends on many factors like, category, home state quota.
You can get the idea from the opening and closing rank for differend categories and quota from the below link:

http://www.askiitians.com/iit-jee/main/counselling/nit-tiruchirappalli.html

Thanks.